Anti-human MUC1 antibody Fab fragment

ABSTRACT

The problem to be solved is to provide an anti-human MUC1 antibody Fab fragment that is expected to be useful in the diagnosis and/or treatment of a cancer, particularly, the diagnosis and/or treatment of breast cancer or bladder cancer, and a diagnosis approach and/or a treatment approach using a conjugate comprising the Fab fragment. The solution is an anti-human MUC1 antibody Fab fragment comprising a heavy chain fragment comprising a heavy chain variable region consisting of the amino acid sequence represented by SEQ ID NO: 8 or 10, and a light chain comprising a light chain variable region consisting of the amino acid sequence represented by SEQ ID NO: 12, and a conjugate comprising the Fab fragment.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/462,143, filed on May 17, 2019, which was a 371 application ofInternational Patent Application No. PCT/JP2017/041486, filed on Nov.17, 2017, and claims priority to Japanese Patent Application No.2016-224811, filed on Nov. 18, 2016, both of which are incorporatedherein by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a novel anti-human MUC1 antibody Fabfragment. The present invention also relates to a composition fordiagnosis and/or for treatment comprising the anti-human MUC1 antibodyFab fragment, and a method for diagnosing and/or treating a cancer usingthe Fab fragment.

BACKGROUND ART

Mucin 1 (MUC1) is a membrane-bound glycoprotein that is expressed on thelumen side of epithelial cells constituting the epithelial tissues ofthe mammary gland, the trachea and the gastrointestinal tract, etc.(Nat. Rev. Cancer, 2004 January; 4 (1): 45-60). MUC1 is overexpressed incancer cells of breast cancer (Mod. Pathol., 2005 October; 18 (10):1295-304), lung cancer (Hum. Pathol., 2008 January; 39 (1): 126-36),colorectal cancer (Int. J. Oncol., 2000 January; 16 (1): 55-64), bladdercancer (PLoS One, 2014 March; 9 (3): e92742), skin cancer(Histopathology, 2000 September; 37 (3): 218-23), thyroid gland cancer(J. Pathol., 2003 July; 200 (3): 357-69), stomach cancer (J. Pathol.,2000 March; 190 (4): 437-43), pancreatic cancer (Int. J. Oncol., 2004January; 24 (1): 107-13), kidney cancer (Mod. Pathol., 2004 February; 17(2): 180-8), ovary cancer (Gynecol. Oncol., 2007 June; 105 (3): 695-702)and uterine cervical cancer (Am. J. Clin. Pathol., 2004 July; 122 (1):61-9), etc. MUC1 is useful as a target molecule for detecting a cancerfocus (Nat. Rev. Cancer, 2004 January; 4 (1): 45-60; and Pathol. Res.Pract., 2010 Aug. 15; 206 (8): 585-9).

MUC1 undergoes the O-glycosylation of threonine at position 9 of a20-amino acid tandem repeat sequence HGVTSAPDTRPAPGSTAPPA (SEQ ID NO:15) present in an extracellular domain. In cancer cells, thisO-glycosylation is incomplete, and 0-glycosylation such as T(Galβ1-3GalNAcα1-O-Ser/Thr), Tn(GalNAcα1-O-Ser/Thr) and2,3ST(Neu5Acα2-3Galβ1-3GalNAcα-O-Ser/Thr) is known to occur in acancer-specific manner (PTL 1 and NPL 1). Since MUC1 in normal tissuesdoes not undergo such cancer-specific O-glycosylation, humancancer-specific MUC1 is particularly useful as a target molecule fortreating various cancers in humans.

For example, a 1B2 antibody (PTL 1), a PankoMab antibody (NPL 2), and a5E5 antibody (PTL 2) are known as antibodies against such humancancer-specific MUC1. Among these antibodies, the 1B2 antibody has beenreported to have high specificity for human cancer-specific MUC1 ascompared with the PankoMab antibody (PTL 1). It has also been reportedthat the dissociation constant of the 1B2 antibody is 3.7×10⁻¹⁰ M (PTL1), and the dissociation constant of the 5E5 antibody is 1.7×10⁻⁹ M (NPL1).

Meanwhile, there are also great needs for the visualization of cancerlesion. First, there are the needs for the early detection of cancerlesion. Current diagnostic modalities such as X-ray photography,echography, computed tomography (CT), magnetic resonance imaging (MRI),positron emission tomography (PET), and single photon emission computedtomography (SPECT) cannot sensitively detect micro cancers. If microcancers can be detected, a primary cancer can be cured by operation orradiotherapy or even a metastatic cancer is curable for alife-sustaining way by early pharmaceutical intervention. Next, thereare the needs for the differentiation between a cancer lesion and abenign lesion. The current diagnostic modalities often misdiagnose abenign lesion as a cancer lesion. If differentiation can be made betweena cancer lesion and a benign lesion, unnecessary biopsy can bedecreased. Furthermore, there are the needs for the intraoperativevisualization of cancer lesion. At present, the position or extent of acancer lesion cannot be accurately determined during the operation ofcancers including breast cancer, bladder cancer, and skin cancer.Therefore, the cancer lesion cannot be completely resected, and there isa risk of ending the operation while leaving the cancer cells. Moreover,there are the needs for the correct determination of the positions ofcancer lesion. Even if postoperative recurrence and metastasis aresuspected due to the elevation of a tumor marker in blood, the currentdiagnostic modalities cannot visualize a metastatic micro cancer.Therefore, the optimum treatment cannot be selected because whether ornot the cancer has actually metastasized or which organ the cancer hasmetastasized to cannot be determined. Thus, it is also useful tovisualize cancer lesion by molecular imaging techniques such asfluorescent imaging and γ-ray imaging (PET and SPECT) using an antibodyspecifically binding to human cancer-specific MUC1 as an in vivodiagnostic drug. However, any previous case using an anti-humancancer-specific MUC1 antibody as an in vivo diagnostic drug has not beenknown.

There is the further needs for a cancer therapeutic drug such as drugconjugated an antibody. The antibody drug is expected as a method fortreating a cancer with fewer adverse reactions because of specificdelivery to a cancer lesion. Radioimmunotherapy using an antibody boundto a radioisotope (Takashi Tsuruo, “Molecular Target Therapy of Cancer”,NANZANDO Co., Ltd., published on Sep. 15, 2008, p. 332-336; J. Nucl.Med., 2016 July; 57 (7): 1105-1111; and Nucl. Med. Biol., 2010 November;37 (8): 949-955), photoimmunotherapy using an antibody bound toIRDye700DX (Nat. Med., 2011 December; 17 (12): 1685-91), and the likehave been reported. IRDye700DX is a near-infrared fluorescent dye thatcan also be used in diagnosis. It has been reported that cell death canbe induced in a cancer-specific manner through the phototoxic effect ofIRDye700DX by binding this to an antibody against an antigen expressedon a cancer cell membrane, and allowing the resultant to specificallyaccumulate in cancer tissues, followed by irradiation with near-infraredlight (Nat. Med., 2011 December; 17 (12): 1685-91). However, anyprevious case of clinically applying an antibody drug of an anti-humancancer-specific MUC1 antibody bound to a cancer therapeutic drug has notbeen known.

In general, antibodies have a long half-life in blood and require aperiod as long as 4 days to 5 days for reaching a tumor-to-blood ratiothat confers a signal-to-background ratio sufficient for visualizing acancer, after administration into the body (Clin. Pharmacol. Ther., 2010May; 87 (5): 586-92). Also, the Fc regions of antibodies cause apharmacological effect such as antibody-dependent cellular cytotoxicity(ADCC) or complement-dependent cytotoxicity (CDC) (NPL 1; and Curr.Opin. Biotechnol., 2002 December; 13 (6): 609-14). Furthermore,antibodies highly accumulate in the liver regardless of a target, andcancer cells such as breast cancer are highly to metastasize to theliver. The accumulation in the liver interfere with the detection ofhepatic metastasis at the time of diagnosis of systemic cancer lesion(Clin. Pharmacol. Ther., 2010 May; 87 (5): 586-92).

For example, low-molecular recombinant antibody fragments such as Fab,scFv, diabody, and minibody are expected to be utilized as therapeuticantibodies because of easy reaching to foci with their high tissuepenetration and low cost production by using an expression system in E.coli or yeast. And also, they are reported to be utilized as diagnosticdrug because of their short half-lives in blood and the feature of renalexcretion (Nat. Biotechnol., 2005 September; 23 (9): 1126-36).

CITATION LIST Patent Literature

-   PTL 1: WO2010/050528-   PTL 2: WO2008/040362

Non Patent Literature

-   NPL 1: Glycoconj. J., 2013 April; 30 (3): 227-36-   NPL 2: Cancer Immunol Immunother, 2006 November; 55 (11): 1337-47

SUMMARY OF INVENTION Technical Problem

Monovalent Fab fragments have a molecular weight of approximately 50kDa, which is smaller than antibodies which have a molecular weight ofapproximately 150 kDa, are eliminated by renal excretion, and also havea short half-life in blood. Hence, they reach a tumor-to-blood ratiothat confers a signal-to-background ratio sufficient for visualizing acancer, within 2 to 32 hours after administration. They lack an Fcregion and therefore cause neither ADCC nor CDC. The Fab fragments aretypically eliminated by renal excretion and therefore, do not interferewith the detection of hepatic metastasis. From these features, the Fabfragments can be expected to be more effective as in vivo diagnosticdrugs as compared with antibodies.

However, the binding activity of the Fab fragments is often attenuatedbecause of being monovalent, not divalent. Antibodies must be labeledwith a detectable substance such as a fluorescent dye or a contrastmedium for their utilization as in vivo diagnostic drugs or drugs foruse in photoimmunotherapy methods. A further problem is the attenuationof their binding activity due to labeling with such a substance.

An object of the present invention is to provide an anti-human MUC1antibody Fab fragment that has excellent binding activity and isexpected to accumulate in a cancer focus within a given time (e.g., 24hours) after administration. Another object of the present invention isto provide a composition for diagnosis comprising the Fab fragment and adiagnosis method using the same, and to provide a composition fortreatment comprising the Fab fragment and a treatment method using thesame.

Solution to Problem

The present inventors have conducted considerable diligent studies onthe preparation of an anti-human MUC1 antibody Fab fragment havingexcellent binding activity against human cancer-specific MUC1, andconsequently prepared an anti-human MUC1 antibody Fab fragmentcomprising a heavy chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 8 or SEQ ID NO: 10, and a light chainvariable region consisting of the amino acid sequence represented by SEQID NO: 12 (Example 1) and found that: the anti-human MUC1 antibody Fabfragment has excellent binding activity against human cancer-specificMUC1 (Example 3) and is free from the attenuation of the bindingactivity against human cancer-specific MUC1 by fluorescent labeling andlabeling with a chelating agent (Example 5 and Example 7); and aconjugate comprising the anti-human MUC1 antibody Fab fragment is usefulin the diagnosis of cancers (Example 8, Example 12 and Example 13) andexhibits an antitumor effect in subcutaneously cancer-bearing models(Example 15).

As a result, a diagnosis approach and a treatment approach using theanti-human MUC1 antibody Fab fragment and the conjugate comprising theanti-human MUC1 antibody Fab fragment are provided.

The present invention includes aspects given below as medically orindustrially useful substances and methods.

Specifically, in one aspect, the present invention can be as follows:

[1] An anti-human MUC1 antibody Fab fragment selected from the groupconsisting of the following (a) and (b):

(a) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 8 or SEQ ID NO: 10 and alight chain comprising a light chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 12; and(b) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region derived from a heavychain variable region consisting of the amino acid sequence representedby SEQ ID NO: 8 or SEQ ID NO: 10 by the modification of glutamine atamino acid position 1 of SEQ ID NO: 8 or SEQ ID NO: 10 into pyroglutamicacid, and a light chain comprising a light chain variable regionconsisting of the amino acid sequence represented by SEQ ID NO: 12.[2] The anti-human MUC1 antibody Fab fragment according to [1] which isselected from the group consisting of the following (a) and (b):(a) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:2 or SEQ ID NO: 4 and a light chain consisting of the amino acidsequence represented by SEQ ID NO: 6; and(b) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment derived from a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 2 or SEQ ID NO: 4 by themodification of glutamine at amino acid position I of SEQ ID NO: 2 orSEQ ID NO: 4 into pyroglutamic acid, and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6.[3] The anti-human MUC1 antibody Fab fragment according to [1] which isselected from the group consisting of the following (a) and (b):(a) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 10 and a light chaincomprising a light chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 12; and(b) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region derived from a heavychain variable region consisting of the amino acid sequence representedby SEQ ID NO: 10 by the modification of glutamine at amino acid position1 of SEQ ID NO: 10 into pyroglutamic acid, and a light chain comprisinga light chain variable region consisting of the amino acid sequencerepresented by SEQ ID NO: 12.[4] The anti-human MUC1 antibody Fab fragment according to [3] which isselected from the group consisting of the following (a) and (b):(a) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4 and a light chain consisting of the amino acid sequence represented bySEQ ID NO: 6; and(b) an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment derived from a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 4 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 4 into pyroglutamicacid, and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6.[5] The anti-human MUC1 antibody Fab fragment according to [4] which isan anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4 and a light chain consisting of the amino acid sequence represented bySEQ ID NO: 6.[6] The anti-human MUC1 antibody Fab fragment according to [4] which isan anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment derived from a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 4 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 4 into pyroglutamicacid, and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6.[7] A conjugate comprising one or more labeling moiety and theanti-human MUC1 antibody Fab fragment according to any of [1] to [6].[8] The conjugate according to [7], wherein the labeling moiety is (i) aligand and a linker, (ii) a ligand, (iii) a fluorescent dye and alinker, or (iv) a fluorescent dye.[9] The conjugate according to [8], wherein the labeling moiety is (i) aligand and a linker or (ii) a ligand.[10] The conjugate according to [9], wherein the ligand is a ligandrepresented by the following formula (A):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment or the linker.[11] The conjugate according to [10], wherein the labeling moiety is aligand and a linker represented by the following formula (A′):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment.[12] The conjugate according to [11], wherein the anti-human MUCantibody Fab fragment is bound via an amino group thereof to the carbonatom of a labeling moiety terminal C(═S) group.[13] A conjugate selected from the group consisting of the following (a)to (c):(a) the conjugate according to [12] wherein the anti-human MUC1 antibodyFab fragment is the anti-human MUC1 antibody Fab fragment according to[5];(b) the conjugate according to [12] wherein the anti-human MUC1 antibodyFab fragment is the anti-human MUC1 antibody Fab fragment according to[6]; and(c) a conjugate which is a mixture of (a) and (b).[14] The conjugate according to any of [9] to [13], further comprising ametal.[15] The conjugate according to [14], wherein the metal is a metalradioisotope.[16] The conjugate according to [15], wherein the metal is ⁸⁹Zr.[17] The conjugate according to [13], further comprising ⁸⁹Zr.[18] The conjugate according to [8], wherein the labeling moiety is (i)a fluorescent dye and a linker or (ii) a fluorescent dye.[19] The conjugate according to [18], wherein the fluorescent dye is afluorescent dye selected from the group consisting of the followingformula (B) and the following formula (C):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment or the linker.[20] The conjugate according to [19], wherein the wavy line representsbinding to the anti-human MUC1 antibody Fab fragment, and the anti-humanMUC1 antibody Fab fragment is bound via an amino group thereof to thecarbon atom of a labeling moiety terminal C(═O) group.[21] The conjugate according to [20], wherein the labeling moiety is afluorescent dye represented by formula (B).[22] A conjugate selected from the group consisting of the following (a)to (c):(a) the conjugate according to [21] wherein the anti-human MUC1 antibodyFab fragment is the anti-human MUC1 antibody Fab fragment according to[5];(b) the conjugate according to [21] wherein the anti-human MUC1 antibodyFab fragment is the anti-human MUC1 antibody Fab fragment according to[6]; and(c) a conjugate which is a mixture of (a) and (b).[23] The conjugate according to [20], wherein the labeling moiety is afluorescent dye represented by formula (C).[24] A conjugate selected from the group consisting of the following (a)to (c):(a) the conjugate according to [23] wherein the anti-human MUC1 antibodyFab fragment is the anti-human MUC1 antibody Fab fragment according to[5];(b) the conjugate according to [23] wherein the anti-human MUC1 antibodyFab fragment is the anti-human MUC1 antibody Fab fragment according to[6]; and(c) a conjugate which is a mixture of (a) and (b).[25] A polynucleotide selected from the group consisting of thefollowing (a) and (b):(a) a polynucleotide comprising a nucleotide sequence encoding the heavychain fragment of the anti-human MUC1 antibody Fab fragment according to[1]; and(b) a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [1].[26] A polynucleotide selected from the group consisting of thefollowing (a) and (b):(a) a polynucleotide comprising a nucleotide sequence encoding the heavychain fragment of the anti-human MUC1 antibody Fab fragment according to[5]; and(b) a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [5].[27] An expression vector comprising the following (a) and/or (b):(a) a polynucleotide comprising a nucleotide sequence encoding the heavychain fragment of the anti-human MUC1 antibody Fab fragment according to[1]; and(b) a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [1].[28] An expression vector comprising the following (a) and/or (b):(a) a polynucleotide comprising a nucleotide sequence encoding the heavychain fragment of the anti-human MUC1 antibody Fab fragment according to[5]; and(b) a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [5].[29] A host cell selected from the group consisting of the following (a)to (d):(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [1];(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment according to [1];(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [1]and a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [1]; and(d) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [1]and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding the light chain of the anti-human MUC1antibody Fab fragment according to [1].[30] A host cell selected from the group consisting of the following (a)to (d):(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [5];(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment according to [5];(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [5]and a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [5]; and(d) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [5]and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding the light chain of the anti-human MUC1antibody Fab fragment according to [5].[31] A method for producing an anti-human MUC1 antibody Fab fragmentcomprising the step of culturing a host cell selected from the groupconsisting of the following (a) to (c) to express the anti-human MUC1antibody Fab fragment:(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [1]and a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [1];(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [1]and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding the light chain of the anti-human MUC1antibody Fab fragment according to [1]; and(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [1],and a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment according to [1].[32] A method for producing an anti-human MUC1 antibody Fab fragmentcomprising the step of culturing a host cell selected from the groupconsisting of the following (a) to (c) to express the anti-human MUC1antibody Fab fragment:(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [5]and a polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment according to [5];(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [5]and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding the light chain of the anti-human MUC1antibody Fab fragment according to [5]; and(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment according to [5],and a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment according to [5].[33] A method for producing a conjugate comprising a labeling moiety andan anti-human MUC1 antibody Fab fragment, comprising the steps of:producing the anti-human MUC1 antibody Fab fragment by the methodaccording to [31] or [32]; and covalently binding the Fab fragment tothe labeling moiety.[34] The method for producing a conjugate according to [33], wherein thestep of covalently binding the Fab fragment to the labeling moiety isthe step of i) binding the Fab fragment via a linker to a ligand or ii)covalently binding the Fab fragment directly to a ligand.[35] The method for producing a conjugate according to [34], furthercomprising the step of labeling the ligand of the conjugate with a metalradioisotope.[36] The method for producing a conjugate according to [33], wherein thestep of covalently binding the Fab fragment to the labeling moiety isthe step of i) binding the Fab fragment via a linker to a fluorescentdye or ii) covalently binding the Fab fragment directly to a fluorescentdye.[37] A composition for diagnosis comprising one or more conjugateaccording to any of [7] to [24], and a pharmaceutically acceptablecarrier.[38] The composition for diagnosis according to [37], wherein theconjugate is the conjugate according to any of [17], [22] and [24].[39] The composition for diagnosis according to [38], wherein theconjugate is the conjugate according to [17].[40] The composition for diagnosis according to [38], wherein theconjugate is the conjugate according to [22].[41] The composition for diagnosis according to [38], wherein theconjugate is the conjugate according to [24].[42] The composition for diagnosis according to any of [37] to [41]which is used in the diagnosis of a cancer expressing human MUC1.[43] The composition for diagnosis according to [42], wherein the canceris breast cancer or bladder cancer.[44] A pharmaceutical composition comprising one or more conjugateaccording to any of [7] to [24], and a pharmaceutically acceptablecarrier.[45] The pharmaceutical composition according to [44], wherein theconjugate is the conjugate according to any of [17], [22] and [24].[46] The pharmaceutical composition according to [45], wherein theconjugate is the conjugate according to [24].[47] The pharmaceutical composition according to any of [44] to [46]which is a pharmaceutical composition for treating a cancer expressinghuman MUC1.[48] The pharmaceutical composition according to [47], wherein thecancer is breast cancer or bladder cancer.[49] Use of the conjugate according to any of [7] to [24] for theproduction of a composition for the diagnosis of breast cancer orbladder cancer and/or a pharmaceutical composition for treating breastcancer or bladder cancer.[50] The conjugate according to any of [7] to [24] for use in thediagnosis and/or treatment of breast cancer or bladder cancer.[51] A method for diagnosing breast cancer or bladder cancer, comprisingpreoperatively or intraoperatively administering the conjugate accordingto any of [7] to [24] to a subject.[52] A method for treating breast cancer or bladder cancer, comprisingthe step of administering a therapeutically effective amount of theconjugate according to any of [7] to [24].

Advantageous Effects of Invention

The anti-human MUC1 antibody Fab fragment of the present invention hasexcellent binding activity against human cancer-specific MUC1 and isexpected to be useful in the diagnosis and/or treatment of cancers suchas breast cancer.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph and a table showing the binding activity of P10-1 Fab,P10-2 Fab and 1B2 Fab of Comparative Example against humancancer-specific MUC1.

FIG. 2 is a graph and a table showing the binding activity of P10-1 FabDye, P10-2 Fab Dye and 1B2 Fab Dye of Comparative Example against humancancer-specific MUC1.

FIG. 3 is a graph and a table showing the binding activity of P10-2 FabDFO and P10-2 Fab against human cancer-specific MUC1.

FIG. 4 is a graph showing the binding activity of P10-2 Fab againstbreast cancer cell line MDA-MB-468 cells (also referred to as MM-468cells) and bladder cancer cell line 647-V cells expressing humancancer-specific MUC1. The horizontal axis depicts the concentration(Log(mg/mL)) of P10-2 Fab, and the vertical axis depicts luminescence.

FIG. 5A is representative photographs taken with a usual camera (left)and a near-infrared fluorescence camera (center and right) 6 hours afteradministration of P10-2 Fab Dye which was intravenously administered at3 mg/kg to subcutaneously cancer-bearing models.

FIG. 5B is a graph quantifying the tumor/background ratio of a tumorsite and a peritumoral background site and indicates mean+standarderror. The horizontal axis depicts the dose and time afteradministration of P10-2 Fab Dye.

FIG. 6 is a graph quantifying luminescence of the tumor sites ofadministering P10-2 Fab IR700 to MM-468 cell-transplanted mice,euthanizing the animals 2 hours after the administration, excisingtumor, taking photographs with IVIS SPECTRUM. The vertical axis depictsluminescence.

FIG. 7 is a graph showing results of measuring cytotoxicity of reactingP10-2 Fab IR700 to MM-468 cells, 647-V cells or CHO-K1 cells withirradiating light of Comparative Example. The upper column of thehorizontal axis of each graph depicts the concentration of P10-2 FabIR700, and the lower column depicts the exposure of light. The verticalaxis depicts luminescence and indicates mean+standard error.

FIG. 8 is a graph showing results of measuring an antitumor effectdepending on the presence or absence of light irradiation (0 J or 200 J)at the time of P10-2 Fab IR700 administration using MM-468cell-transplanted nude mice. The horizontal axis depicts the number ofdays when the day on which tumor volume became 300 mm³ was defined asday 1. The vertical axis depicts tumor volume (mm³) and indicatesmean+standard error.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present invention will be described in detail. However,the present invention is not limited thereby. Scientific terms andtechnical terms used in relation to the present invention have meaningsgenerally understood by those skilled in the art, unless otherwisespecified herein.

The present inventors have conducted considerable diligent studies onthe preparation of an anti-human cancer-specific MUC1 antibody or anantigen binding fragment thereof and consequently successfully preparedan anti-human MUC1 antibody Fab fragment having the ability to stronglybind to cancer-specific MUC1.

The basic structure of an antibody molecule is common among classes andis constituted by heavy chains having a molecular weight of 50000 to70000 and light chains having a molecular weight of 20000 to 30000. Theheavy chain usually consists of a polypeptide chain comprisingapproximately 440 amino acids, has a structure characteristic of eachclass, and is called γ, μ, α, δ, and ε chains corresponding to IgG, IgM,IgA, IgD, and IgE. IgG further has IgG1, IgG2, IgG3, and IgG4 which arecalled γ1, γ2, γ3, and γ4, respectively. The light chain usuallyconsists of a polypeptide chain comprising approximately 220 amino acidsand known as two types, L and K types, which are called λ and κ chains,respectively. As for the peptide configuration of the basic structure ofthe antibody molecule, two homologous heavy chains and two homologouslight chains are linked through disulfide bonds (S—S bonds) andnon-covalent bonds to form a molecular weight of 150000 to 190000. Thetwo light chains can pair with any of the heavy chains. An individualantibody molecule is constantly made up of two identical light chainsand two identical heavy chains.

Four (or five for t and E chains) and two intrachain S—S bonds arepresent in the heavy chain and the light chain, respectively, and eachconstitute one loop per 100 to 110 amino acid residues. Thisconformation is similar among the loops and is called structural unit ordomain. For both the heavy chain and the light chain, a domainpositioned at the N terminus does not have a constant amino acidsequence even among preparations from the same classes (subclasses) ofanimals of the same species, and is thus called variable region. Therespective domains are called heavy chain variable region (VH domain)and light chain variable region (VL domain). An amino acid sequence onthe C-terminal side therefrom is almost constant on a class or subclassbasis and called constant region. The respective domains are representedby CH1, CH2, CH3 and CL.

The binding specificity of the antibody for an antigen depends on theamino acid sequence of a moiety constituted by the heavy chain variableregion and the light chain variable region. On the other hand,biological activity such as binding to complements or various cellsreflects the difference in structure among the constant regions of Igsof respective classes. It is known that the variability of the heavychain and light chain variable regions is limited substantially by threesmall hypervariable regions present in both the chains. These regionsare called complementarity determining regions (CDRs; CDR1, CDR2, andCDR3 in order from the N-terminal side). The remaining moieties of thevariable region are called framework regions (FRs) and are relativelyconstant.

A region between the CH1 domain and the CH2 domain of the heavy chainconstant region of an antibody is called hinge region. This region isrich in proline residues and contains a plurality of interchain S—Sbonds that connect two heavy chains. For example, the hinge regions ofhuman IgG1, IgG2, IgG3, and IgG4 contain 2, 4, 11, and 2 cysteineresidues, respectively, which constitute S—S bonds between the heavychains. The hinge region is a region highly sensitive to a proteolyticenzyme such as papain or pepsin. In the case of digesting an antibodywith papain, the heavy chains are cleaved at a position on theN-terminal side from the inter-heavy chain S—S bonds of the hinge regionand thus decomposed into two Fab fragments and one Fc fragment. The Fabfragment is constituted by a light chain and a heavy chain fragmentcomprising a heavy chain variable region (VH), a CH1 domain and aportion of the hinge region. The Fab fragment comprises variable regionsand has antigen binding activity.

<Anti-Human MUC1 Antibody Fab Fragment of Present Invention>

The anti-human MUC1 antibody Fab fragment of the present invention is aFab fragment having the following feature:

an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 8 or SEQ ID NO: 10 and alight chain comprising a light chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 12.

In one embodiment, the anti-human MUC1 antibody Fab fragment of thepresent invention is an anti-human MUC1 antibody Fab fragment comprisinga heavy chain fragment comprising a heavy chain variable regionconsisting of the amino acid sequence represented by SEQ ID NO: 10 and alight chain comprising a light chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 12.

Any constant region of Igγ1, Igγ2, Igγ3 or Igγ4, etc. can be selectableas the heavy chain constant region of the anti-human MUC1 antibody Fabfragment of the present invention. In one embodiment, the heavy chainconstant region of the anti-human MUC1 antibody Fab fragment of thepresent invention is a human Igγ1 constant region.

Any constant region of Igλ or Igκ can be selectable as the light chainconstant region of the anti-human MUC1 antibody Fab fragment of thepresent invention. In one embodiment, the light chain constant region ofthe anti-human MUC1 antibody Fab fragment of the present invention is ahuman Igκ constant region.

In one embodiment, the anti-human MUC1 antibody Fab fragment of thepresent invention is the following Fab fragment:

an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:2 or SEQ ID NO: 4 and a light chain consisting of the amino acidsequence represented by SEQ ID NO: 6.

In one embodiment, the anti-human MUC1 antibody Fab fragment of thepresent invention is an anti-human MUC1 antibody Fab fragment comprisinga heavy chain fragment consisting of the amino acid sequence representedby SEQ ID NO: 4 and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6.

In the case of expressing an antibody including a Fab fragment in cells,the antibody is known to undergo a posttranslational modification.Examples of the posttranslational modification include the cleavage ofheavy chain C-terminal lysine by carboxypeptidase, the modification ofheavy chain and light chain N-terminal glutamine or glutamic acid intopyroglutamic acid by pyroglutamylation, glycosylation, oxidation,deamidation, and glycation. Such a posttranslational modification isknown to occur in various antibodies (J. Pharm. Sci., 2008; 97:2426-2447).

The anti-human MUC1 antibody Fab fragment of the present invention canalso include a Fab fragment resulting from the posttranslationalmodification. Examples of the anti-human MUC1 antibody Fab fragment ofthe present invention resulting from the posttranslational modificationinclude an anti-human MUC1 antibody Fab fragment having an N-terminallypyroglutamylated heavy chain. It is known in the art that such aposttranslational modification by N-terminal pyroglutamylation has noinfluence on the activity of the antibody (Anal. Biochem., 2006; 348:24-39).

In one embodiment, the anti-human MUC1 antibody Fab fragment of thepresent invention is an anti-human MUC1 antibody Fab fragment having thefollowing feature:

an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region derived from a heavychain variable region consisting of the amino acid sequence representedby SEQ ID NO: 8 or SEQ ID NO: 10 by the modification of glutamine atamino acid position 1 of SEQ ID NO: 8 or SEQ ID NO: 10 into pyroglutamicacid, and a light chain comprising a light chain variable regionconsisting of the amino acid sequence represented by SEQ ID NO: 12.

In a certain embodiment, the anti-human MUC1 antibody Fab fragment ofthe present invention is an anti-human MUC1 antibody Fab fragment havingthe following feature:

an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region derived from a heavychain variable region consisting of the amino acid sequence representedby SEQ ID NO: 10 by the modification of glutamine at amino acid position1 of SEQ ID NO: 10 into pyroglutamic acid, and a light chain comprisinga light chain variable region consisting of the amino acid sequencerepresented by SEQ ID NO: 12.

In an alternative embodiment, the anti-MUC1 antibody Fab fragment of thepresent invention is an anti-human MUC1 antibody Fab fragment having thefollowing feature:

an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment derived from a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 2 or SEQ ID NO: 4 by themodification of glutamine at amino acid position 1 of SEQ ID NO: 2 orSEQ ID NO: 4 into pyroglutamic acid, and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6.

In a certain embodiment, the anti-MUC1 antibody Fab fragment of thepresent invention is an anti-human MUC1 antibody Fab fragment having thefollowing feature:

an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment derived from a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 4 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 4 into pyroglutamicacid, and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6.

The anti-human MUC1 antibody Fab fragment of the present invention bindsto human cancer-specific MUC1. The cancer-specific MUC1 is expressed incancers such as breast cancer, lung cancer, colorectal cancer, bladdercancer, skin cancer, thyroid gland cancer, stomach cancer, pancreaticcancer, kidney cancer, ovary cancer or uterine cervical cancer. A methodfor measuring the binding activity of the obtained anti-human MUC1antibody Fab fragment against human cancer-specific MUC1 includesmethods such as ELISA and FACS. In the case of using, for example,ELISA, human cancer-specific MUC1-positive cells (e.g., T-47D cells) areimmobilized onto an ELISA plate, to which the Fab fragment is then addedand reacted, and then, an anti-Igκ antibody or the like labeled withhorseradish peroxidase or the like is reacted. Then, the binding of thesecondary antibody is identified by activity measurement using a reagentfor detecting the activity thereof (e.g., a chemiluminescent horseradishperoxidase substrate for the horseradish peroxidase label) or the like.

The anti-human MUC1 antibody Fab fragment of the present invention canbe readily prepared by those skilled in the art using a method known inthe art on the basis of sequence information on the heavy chain fragmentand the light chain of the anti-human MUC1 antibody Fab fragment of thepresent invention disclosed herein. The anti-human MUC1 antibody Fabfragment of the present invention can be produced according to, but notparticularly limited to, a method described in, for example, <Method forproducing anti-human MUC1 antibody Fab fragment according to presentinvention> mentioned later.

<Conjugate of Present Invention>

The conjugate of the present invention is a conjugate comprising alabeling moiety and the anti-human MUC1 antibody Fab fragment of thepresent invention.

The “labeling moiety” is (i) a ligand and a linker, (ii) a ligand, (iii)a fluorescent dye and a linker, or (iv) a fluorescent dye. A certainembodiment is (i) a ligand and a linker, or (ii) a ligand. A certainembodiment is (i) a fluorescent dye and a linker, or (ii) a fluorescentdye. The ligand of the “labeling moiety” may further comprise a metal. Acertain embodiment is (i) a ligand and a linker or (ii) a ligandcomprising a metal, and in other words, is (i) a ligand that has formeda chelate complex with a metal, and a linker, or (ii) a ligand that hasformed a chelate complex with a metal.

The conjugate of the present invention comprising a metal or afluorescent dye can be used in various contrast media and/or cancertherapeutic agents and is used in, for example, an MRI contrast medium,a PET tracer, a fluorescently labeled molecular imaging agent, and adrug for use in photoimmunotherapy methods.

In the present specification, the “metal” means a paramagnetic metal ionor a metal radioisotope.

The paramagnetic metal ion is suitably used in an MRI contrast medium.Examples of the embodiment of the paramagnetic metal ion include, butare not limited to, Fe²⁺, Fe³⁺, Cu²⁺, Ni²⁺, Rh²⁺, Co²⁺, Gd³⁺, Eu³⁺,Dy³⁺, Tb³⁺, Pm³⁺, Nd³⁺, Tm³⁺, Ce³⁺, Y³⁺, Ho³⁺, Er³⁺, La³⁺, Yb³⁺, Mn³⁺,and Mn²⁺. A certain embodiment is Gd³⁺, Mn³⁺, Mn²⁺, Fe²⁺, or Fe³⁺. Acertain embodiment is Mn³⁺ or Mn²⁺. In this case, halogen or the likecan be used as a counter anion in the conjugate. Alternatively, thecounter anion may be C(═O)O⁻ of the ligand. The conjugate may furtherhave a counter cation such as Na⁺.

The metal radioisotope is used in, for example, a PET tracer. Examplesof a certain embodiment include, but are not limited to, ⁸⁹Zr, ⁵¹Mn,⁵²Fe, ⁶⁰Cu, ⁶⁷Ga, ⁶⁸Ga, ⁷²As, ^(99m)Tc, and ¹¹¹In. A certain embodimentis ⁸⁹Zr, ⁶⁰Cu, ⁶⁷Ga, ⁶⁸Ga, ⁹⁹mTc, or ¹¹¹In. A certain embodiment is aradioisotope of zirconium. A certain embodiment is ⁸⁹Zr.

The “ligand” is a moiety capable of forming a chelate complex with ametal in the conjugate and means a group constituted by a chelatingagent. The constituted group is a group having a bond by the removal ofa proton from the chelating agent.

The “chelating agent” is a compound that can form a coordinate bond witha metal.

Examples of the “chelating agent” include siderophore andnon-siderophore. Examples of the siderophore include hydroxamic acidtype, catechol type, and mixed ligand type. Examples of the hydroxamicacid-type siderophore include ferrichrome, deferoxamine (DFO)represented by the following formula:

fusarinine C, ornibactin, and rhodotorulic acid. Examples of thecatechol-type siderophore include enterobactin, bacillibactin, andvibriobactin. Examples of the mixed ligand-type siderophore includeazotobactin, pyoverdine, and yersiniabactin. In the case of thesiderophore, DFO can be reacted via its reactive functional group —NH₂with the linker or the Fab fragment, and the siderophore other than DFOcan also be reacted via its reactive functional group such as a carboxygroup, a hydroxy group, or an amino group with the linker or the Fabfragment by a method usually used by those skilled in the art.

Examples of the non-siderophore include DTPA(diethylenetriaminepentaacetic acid, CAS No: 67-43-6), DTPA-BMA(1,7-bis(methylcarbamoylmethyl)-1,4,7-triazaheptane-1,4,7-triaceticacid, CAS No: 119895-95-3), EOB-DTPA (DTPA bound to an ethoxybenzylgroup, CAS No: 158599-72-5), TTHA (triethylenetetraminehexaacetic acid,CAS No: 869-52-3), DO3A (1,4,7,10-tetraazacyclododecane-1,4,7-triaceticacid, CAS No: 217973-03-0), HP-DO3A(10-(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triaceticacid, CAS No: 120041-08-9), DOTA(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, CAS No:60239-18-1), and known reactive derivatives thereof.

Compounds and conjugates described herein also encompass free forms andsalts thereof unless otherwise specified. In this context, the “saltthereof” is a salt that can be formed by the compound or the conjugatethat may form an acid-addition salt or a salt with a base depending onthe type of a substituent in the compound or the conjugate. Specificexamples thereof include: acid-addition salts with inorganic acids suchas hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid,nitric acid, and phosphoric acid, or organic acids such as formic acid,acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid,fumaric acid, maleic acid, lactic acid, malic acid, mandelic acid,tartaric acid, dibenzoyltartaric acid, ditoluoyltartaric acid, citricacid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid,p-toluenesulfonic acid, aspartic acid, and glutamic acid; salts withinorganic bases such as sodium, potassium, magnesium, calcium, andaluminum, or organic bases such as methylamine, ethylamine,ethanolamine, lysine, and ornithine; salts with various amino acids andamino acid derivatives, such as acetylleucine; and ammonium salts. Forexample, DFO exists as deferoxamine methanesulfonate or exists as othersalts. DTPA exits both as a free form and as sodium salt.

A certain embodiment of the “chelating agent” for use in an MRI contrastmedium is the siderophore or non-siderophore chelating agent describedabove.

A certain embodiment of the “chelating agent” for use in a PET tracer isthe siderophore or non-siderophore chelating agent described above. Acertain embodiment is MAG3 (mercapto-acetyl-glycine-glycine-glycine, CASNo: 66516-09-4). A certain embodiment is DFO.

Examples of a certain embodiment of the “chelating agent” constitutingthe ligand contained in the conjugate of the present invention includeDFO, DTPA, DTPA-BMA, EOB-DTPA, DO3A, HP-DO3A, and DOTA. A certainembodiment is DFO, DTPA, or DOTA. A certain embodiment is DFO.

The “linker is a group that creates a distance between the anti-humanMUC1 antibody Fab fragment and the ligand. Examples of a certainembodiment of the “linker” in the conjugate include the followingformula:

(hereinafter, referred to as —C(═S)—NH-(1,4-phenylene)-NH—C(═S)—),—CH₂-(1,4-phenylene)-NH—C(═S)—, and —C(═O)—(C₁₋₂₀ alkylene)-C(═O)—. Inthis context, the “C₁₋₂₀ alkylene” is linear or branched alkylene having1 to 20 carbon atoms. A certain embodiment of the C₁₋₂₀ alkylene isC₁₋₁₀ alkylene or C₁₋₂ alkylene. A certain embodiment of the C₁₋₂₀alkylene is ethylene. A certain embodiment is—C(═S)—NH-(1,4-phenylene)-NH—C(═S)—. A certain embodiment is—C(═O)—C₂H₄—C(═O)—. Examples of a reagent that can be used as the linkerinclude HO—C(═O)—(C₁₋₂₀ alkylene)-C(═O)—OH, succinic acid, andp-di-NCS-benzene(p-diisocyanobenzene).

The conjugate of the present invention comprising a fluorescent dye canbe used as a fluorescently labeled molecular imaging agent, a drug foruse in photoimmunotherapy methods, or a fluorescently labeled molecularimaging agent and a drug for use in photoimmunotherapy methods.

A dye having absorption maximum and emission maximum at a near-infraredwavelength (650 to 1000 nm) usually used in photoimaging can be used asthe fluorescent dye for use in the conjugate of the present invention.Examples of a certain embodiment of the fluorescent dye include cyanineand indocyanine compounds. Examples of a certain embodiment includeIRDye800CW and IRDye700DX (LI-COR Bioscience, Inc.), Cy (MolecularProbes, Inc.), Alexa Fluor, BODIPY, and DyLight (Thermo FisherScientific Inc.), CF790 (Biotium, Inc.), DY (Dyomics GmbH), HiLyte Fluor680 and HiLyte Fluor 750 (AnaSpec Inc.), and PULSAR650 and QUASAR670(LGC Biosearch Technologies). A certain embodiment is IRDye800CWrepresented by the following formula:

or IRDye700DX represented by the following formula:

The fluorescent dye can be reacted via its carboxy group, hydroxy group,amino group, or the like or via an active group introduced by a methodusually used by those skilled in the art with the Fab fragment or thelinker. A certain embodiment of the fluorescent dye having an introducedactive group is a fluorescent dye esterified with a N-hydroxysuccinimide(NHS) group. For example, NHS esters of IRDye800CW and IRDye700DXmentioned above are commercially available, and they can be utilized.

The binding of the anti-human MUC1 antibody Fab fragment of the presentinvention to the labeling moiety can be appropriately performed by thoseskilled in the art using a known approach. For example, the labelingmoiety can be bound to one or more amino groups (e.g., a N-terminalamino group and an amino group of an amino acid side chain), one or morethiol groups (e.g., a thiol group of an amino acid side chain), or oneor more carboxyl groups (e.g., carboxyl groups of the C terminus and anamino acid side chain) of the anti-human MUC1 antibody Fab fragment ofthe present invention. A certain embodiment of the conjugate of thepresent invention is a conjugate wherein the labeling moiety is bound toone or more amino groups of the anti-human MUC1 antibody Fab fragment ofthe present invention.

When the labeling moiety is a ligand and a linker, the conjugate of thepresent invention may be produced by reacting the chelating agent with asubstance obtained through the reaction of the anti-human MUC1 antibodyFab fragment of the present invention with the linker. It may beproduced by reacting the anti-human MUC1 antibody Fab fragment of thepresent invention with a substance obtained through the reaction of thechelating agent with the linker. As a reaction example, a substanceobtained through the reaction of the amino group of the chelating agentwith the linker may be reacted with one or more amino groups (e.g., anN-terminal amino group and an amino group of a lysine side chain) of theanti-human MUC1 antibody Fab fragment of the present invention. Reactionof synthesizing thiourea by adding isothiocyanate to amine, reaction ofsynthesizing amide by adding amine and carboxylic acid, or the like canbe used in the production of the conjugate. The reaction can beperformed by the application of a method known to those skilled in theart. A compound of the chelating agent bound to the linker in advancemay be used as a starting material. Examples of the compound of thechelating agent bound to the linker include p-SCN-Bn-DFO (DFO bound to ap-isothiocyanophenylaminothiocarbonyl group, CAS No: 1222468-90-7)represented by the following formula:

DTPA bound to a p-isothiocyanobenzyl group (p-NCS-Bn-DTPA, CAS No:102650-30-6), DOTA bound to a p-isothiocyanobenzyl group (p-NCS-Bn-DOTA,CAS No: 127985-74-4), and p-SCN-Bn-CHX-A″-DTPA([(R)-2-amino-3-(4-isothiocyanatophenyl)propyl]-trans-(S,S)-cyclohexane-1,2-diamine-pentaaceticacid, CAS No: 157380-45-5).

The metal (paramagnetic metal ion or metal radioisotope) can be added tothe anti-human MUC1 antibody Fab fragment of the present invention boundto one or more labeling moiety thus produced by the production method toobtain the conjugate of the present invention comprising the metal.

Also, the conjugate of the present invention may be produced as aconjugate which is a Fab fragment bound via an amino group thereof toone or more labeling moiety by reacting one or more amino groups (e.g.,a N-terminal amino group and an amino group of an amino acid side chain)of the Fab fragment with the labeling moiety having a carboxyl group oran isothiocyanic acid group activated with N-hydroxysuccinimide (NHS).

The conjugate of the present invention is a conjugate comprising one ormore labeling moiety and the anti-human MUC1 antibody Fab fragment ofthe present invention. A certain embodiment is the anti-human MUC1antibody Fab fragment bound to 1 to 27 labeling moieties. A certainembodiment is the anti-human MUC1 antibody Fab fragment bound to 1 to 23labeling moieties. A certain embodiment is the anti-human MUC1 antibodyFab fragment bound to 1 to 15 labeling moieties. A certain embodiment isthe anti-human MUC1 antibody Fab fragment bound to 1 to 11 labelingmoieties. A certain embodiment is the anti-human MUC1 antibody Fabfragment bound to 1 to 9 labeling moieties. A certain embodiment is theanti-human MUC1 antibody Fab fragment bound to 1 to 7 labeling moieties.A certain embodiment is the anti-human MUC1 antibody Fab fragment boundto 1 to 5 labeling moieties. A certain embodiment is the anti-human MUC1antibody Fab fragment bound to 1 to 4 labeling moieties. A certainembodiment is the anti-human MUC1 antibody Fab fragment bound to one ormore labeling moiety further comprising a metal.

In one embodiment, the conjugate of the present invention is a conjugatewherein the labeling moiety is (i) a ligand and a linker, (ii) a ligand,(iii) a fluorescent dye and a linker, or (iv) a fluorescent dye.

In a certain embodiment, examples of the conjugate of the presentinvention include the followings:

(1) a conjugate wherein the anti-human MUC1 antibody Fab fragment is ananti-human MUC1 antibody Fab fragment comprising a heavy chain fragmentcomprising a heavy chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 10 and a light chain comprising alight chain variable region consisting of the amino acid sequencerepresented by SEQ ID NO: 12;(2) the conjugate of (1), wherein the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment consisting of the amino acid sequence represented by SEQID NO: 4 and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6;(3) a conjugate wherein the anti-human MUC1 antibody Fab fragment is ananti-human MUC1 antibody Fab fragment comprising a heavy chain fragmentcomprising a heavy chain variable region derived from a heavy chainvariable region consisting of the amino acid sequence represented by SEQID NO: 10 by the modification of glutamine at amino acid position 1 ofSEQ ID NO: 10 into pyroglutamic acid, and a light chain comprising alight chain variable region consisting of the amino acid sequencerepresented by SEQ ID NO: 12;(4) the conjugate of (2), wherein the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment derived from a heavy chain fragment consisting of theamino acid sequence represented by SEQ ID NO: 4 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 4 into pyroglutamicacid, and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6;(5) the conjugate of any of (1) to (4), wherein the labeling moiety is(i) a ligand and a linker, or (ii) a ligand;(6) the conjugate of any of (1) to (4), wherein the ligand is a groupconstituted by a chelating agent selected from the group consisting ofDFO, DTPA, DTPA-BMA, EOB-DTPA, DO3A, HP-DO3A and DOTA, and the linker isa linker selected from the group consisting of—C(═S)—NH-(1,4-phenylene)-NH—C(═S)—, —CH₂-(1,4-phenylene)-NH—C(═S)— and—C(═O)—(C₁₋₂₀ alkylene)-C(═O)—;(7) the conjugate of (6), wherein the ligand is a group constituted by achelating agent selected from the group consisting of DFO, DTPA, andDOTA;(8) the conjugate of (6), wherein the ligand is a group constituted byDFO, and the linker is —C(═S)—NH-(1,4-phenylene)-NH—C(═S)—;(9) the conjugate according to any of (5) to (8), further comprising ametal;(10) the conjugate of (9), wherein the metal is a metal radioisotope;and(11) the conjugate of (10), wherein the metal is ⁸⁹Zr.

In a certain embodiment, the conjugate of the present invention is aconjugate wherein the labeling moiety is (i) a ligand and a linker, or(ii) a ligand.

In a certain embodiment, the conjugate of the present invention is aconjugate wherein the ligand is a ligand represented by the followingformula (A):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment or the linker.

In a certain embodiment, the conjugate of the present invention whereinthe ligand is a ligand represented by formula (A) is a conjugate whereinthe labeling moiety is a ligand and a linker represented by thefollowing formula (A′):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment, andthe anti-human MUC1 antibody Fab fragment is bound via an amino groupthereof to the carbon atom of a labeling moiety terminal C(═S) group.

In a certain embodiment, the conjugate of the present invention is aconjugate wherein the labeling moiety is (i) a ligand and a linker, or(ii) a ligand, the conjugate further comprising a metal. A certainembodiment of the metal is a metal radioisotope. A certain embodiment ofthe metal radioisotope is ⁸⁹Zr.

In an alternative embodiment, the conjugate of the present invention isa conjugate wherein the labeling moiety is (i) a fluorescent dye and alinker, or (ii) a fluorescent dye.

In a certain embodiment, the conjugate of the present invention whereinthe labeling moiety comprises a fluorescent dye is a conjugate whereinthe fluorescent dye is a fluorescent dye selected from the groupconsisting of the following formula (B) and the following formula (C):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment or the linker.

In a certain embodiment, the conjugate of the present invention whereinthe labeling moiety is a fluorescent dye represented by formula (B) is aconjugate wherein the wavy line represents binding to the anti-humanMUC1 antibody Fab fragment, and the anti-human MUC1 antibody Fabfragment is bound via an amino group thereof to the carbon atom of alabeling moiety terminal C(═O) group.

In a certain embodiment, the conjugate of the present invention whereinthe labeling moiety is a fluorescent dye represented by formula (C) is aconjugate wherein the wavy line represents binding to the anti-humanMUC1 antibody Fab fragment, and the anti-human MUC1 antibody Fabfragment is bound via an amino group thereof to the carbon atom of alabeling moiety terminal C(═O) group.

Certain embodiments of the conjugate of the present invention will befurther shown below:

(1) a conjugate wherein the labeling moiety is a ligand and a linkerrepresented by formula (A′), and the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment comprising a heavy chain variable region consisting ofthe amino acid sequence represented by SEQ ID NO: 10 and a light chaincomprising a light chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 12;(2) the conjugate of (1), wherein the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment consisting of the amino acid sequence represented by SEQID NO: 4 and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6;(3) a conjugate wherein the labeling moiety is a ligand and a linkerrepresented by formula (A′), and the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment comprising a heavy chain variable region derived from aheavy chain variable region consisting of the amino acid sequencerepresented by SEQ ID NO: 10 by the modification of glutamine at aminoacid position 1 of SEQ ID NO: 10 into pyroglutamic acid, and a lightchain comprising a light chain variable region consisting of the aminoacid sequence represented by SEQ ID NO: 12;(4) the conjugate of (3), wherein the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment derived from a heavy chain fragment consisting of theamino acid sequence represented by SEQ ID NO: 4 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 4 into pyroglutamicacid, and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6;(5) the conjugate of (2) or (4) which is the anti-human MUC1 antibodyFab fragment bound to 1 to 11 labeling moieties;(6) the conjugate of (2) or (4) which is the anti-human MUC1 antibodyFab fragment bound to 1 to 4 labeling moieties;(7) the conjugate of any of (1) to (6), further comprising a metal;(8) the conjugate of (7), wherein the metal is a metal radioisotope;(9) the conjugate of (8), wherein the metal is ⁸⁹Zr;(10) a conjugate wherein the labeling moiety is a fluorescent dyerepresented by formula (B) or formula (C), and the anti-human MUC1antibody Fab fragment is an anti-human MUC1 antibody Fab fragmentcomprising a heavy chain fragment comprising a heavy chain variableregion consisting of the amino acid sequence represented by SEQ ID NO:10 and a light chain comprising a light chain variable region consistingof the amino acid sequence represented by SEQ ID NO: 12;(11) the conjugate of (10), wherein the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment consisting of the amino acid sequence represented by SEQID NO: 4 and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6;(12) a conjugate wherein the labeling moiety is a fluorescent dyerepresented by formula (B) or formula (C), and the anti-human MUC1antibody Fab fragment is an anti-human MUC1 antibody Fab fragmentcomprising a heavy chain fragment comprising a heavy chain variableregion derived from a heavy chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 10 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 10 into pyroglutamicacid, and a light chain comprising a light chain variable regionconsisting of the amino acid sequence represented by SEQ ID NO: 12;(13) the conjugate of (12), wherein the anti-human MUC1 antibody Fabfragment is an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment derived from a heavy chain fragment consisting of theamino acid sequence represented by SEQ ID NO: 4 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 4 into pyroglutamicacid, and a light chain consisting of the amino acid sequencerepresented by SEQ ID NO: 6;(14) the conjugate of any of (10) to (13), wherein the labeling moietyis a fluorescent dye represented by formula (C);(15) the conjugate of (14) which is the anti-human MUC1 antibody Fabfragment bound to 1 to 11 labeling moieties;(16) the conjugate of (15) which is the anti-human MUC1 antibody Fabfragment bound to 1 to 5 labeling moieties;(17) the conjugate of any of (10) to (13), wherein the labeling moietyis a fluorescent dye represented by formula (B);(18) the conjugate of (17) which is the anti-human MUC1 antibody Fabfragment bound to 1 to 11 labeling moieties; and(19) the conjugate of (18) which is the anti-human MUC1 antibody Fabfragment bound to 1 to 5 labeling moieties.

In an alternative embodiment, the conjugate of the present invention isa conjugate represented by the following formula (I):[Chemical Formula 14](L-X)_(p)-Ab  (I)wherein Ab represents the anti-human MUC1 antibody Fab fragment,L represents (i) a ligand or (ii) a fluorescent dye,X represents a linker or a bond, andp is a natural number of 1 to 27. A certain embodiment of p is a naturalnumber of 1 to 23.A certain embodiment is a natural number of 1 to 15. A certainembodiment is a natural number of 1 to 11. A certain embodiment is anatural number of 1 to 9. A certain embodiment is a natural number of 1to 7. A certain embodiment is a natural number of 1 to 5. A certainembodiment is a natural number of 1 to 4.

In a certain embodiment, the conjugate of the present invention is aconjugate of formula (I), the conjugate further comprising a metal. Acertain embodiment of the metal is a metal radioisotope. A certainembodiment of the metal radioisotope is ⁸⁹Zr.

In a certain embodiment, the conjugate of formula (I) is the conjugateof the present invention wherein the labeling moiety is a ligand and alinker represented by formula (A′). In a certain embodiment, thisconjugate is a conjugate represented by the following formula (II):

wherein Ab represents the anti-human MUC1 antibody Fab fragment, andp is a natural number of 1 to 27. A certain embodiment of p is a naturalnumber of 1 to 23.A certain embodiment is a natural number of 1 to 15. A certainembodiment is a natural number of 1 to 11. A certain embodiment is anatural number of 1 to 9. A certain embodiment is a natural number of 1to 7. A certain embodiment is a natural number of 1 to 5. A certainembodiment is a natural number of 1 to 4.Ab is bound via an amino group thereof to the carbon atom of a labelingmoiety terminal C(═S) group.

In a certain embodiment, the conjugate of the present invention is aconjugate of formula (II), the conjugate further comprising a metal. Acertain embodiment of the metal is a metal radioisotope. A certainembodiment of the metal radioisotope is ⁸⁹Zr.

In a certain embodiment, the conjugate of formula (I) is the conjugateof the present invention wherein the labeling moiety is a fluorescentdye represented by formula (B). In a certain embodiment, the conjugateis a conjugate represented by the following formula (III):

wherein Ab represents the anti-human MUC1 antibody Fab fragment, andp is a natural number of 1 to 27. A certain embodiment of p is a naturalnumber of 1 to 23.A certain embodiment is a natural number of 1 to 15. A certainembodiment is a natural number of 1 to 11. A certain embodiment is anatural number of 1 to 9. A certain embodiment is a natural number of 1to 7. A certain embodiment is a natural number of 1 to 5. A certainembodiment is a natural number of 1 to 4.Ab is bound via an amino group thereof to the carbon atom of a labelingmoiety terminal C(═O) group.

In a certain embodiment, the conjugate of formula (I) is the conjugateof the present invention wherein the labeling moiety is a fluorescentdye represented by formula (C). In a certain embodiment, this conjugateis a conjugate represented by the following formula (IV):

wherein Ab represents the anti-human MUC1 antibody Fab fragment, andp is a natural number of 1 to 27. A certain embodiment of p is a naturalnumber of 1 to 23.A certain embodiment is a natural number of 1 to 15. A certainembodiment is a natural number of 1 to 11. A certain embodiment is anatural number of 1 to 9. A certain embodiment is a natural number of 1to 7. A certain embodiment is a natural number of 1 to 5. A certainembodiment is a natural number of 1 to 4.Ab is bound via an amino group thereof to the carbon atom of a labelingmoiety terminal C(═O) group.

In a certain embodiment, the conjugate of the present invention is theanti-human MUC1 antibody Fab fragment of the present invention labeledwith a detectable molecule. The anti-human MUC1 antibody Fab fragment ofthe present invention labeled with a detectable molecule is theanti-human MUC1 antibody Fab fragment of the present invention and thedetectable molecule linked through a covalent bond directly or via anappropriate linker. In the present specification, the detectablemolecule means every moiety detectable in an imaging diagnosis techniqueknown in the art. When the imaging diagnosis technique is, for example,fluorescence imaging, the detectable molecule is a fluorescent dye. Whenthe imaging diagnosis technique is PET, the detectable molecule is acompound imageable by PET. A certain embodiment is a compound comprisinga ligand labeled with a radionuclide, or a sugar residue labeled with anonmetal radionuclide. A certain embodiment of the compound comprising aligand labeled with a radionuclide is a ligand that has formed a chelatecomplex with a metal radioisotope. When the imaging diagnosis techniqueis MRI, the detectable molecule is a compound detectable by the MRItechnique. A certain embodiment is a compound comprising a labeledligand having a paramagnetic metal ion. A certain embodiment of thecompound comprising a labeled ligand having a paramagnetic metal ion isa ligand that has formed a chelate complex with a paramagnetic metalion.

When the anti-human MUC1 antibody Fab fragment of the present inventionlabeled with a detectable molecule is used in the context of adetectable molecule, the compound imageable by PET is referred to as aPET tracer, and the compound detectable by the MRI technique is referredto as a MRI contrast medium.

Examples of certain embodiments of the anti-human MUC1 antibody Fabfragment of the present invention labeled with a detectable moleculeinclude the followings:

(1) an anti-human MUC1 antibody Fab fragment wherein the detectablemolecule is a fluorescent dye, a PET tracer, or a MRI contrast medium;

(2) the anti-human MUC1 antibody Fab fragment of (1), wherein thedetectable molecule is a fluorescent dye;

(3) the anti-human MUC1 antibody Fab fragment of (2), wherein thedetectable molecule is a fluorescent dye represented by formula (B);

(4) the anti-human MUC1 antibody Fab fragment of (2), wherein thedetectable molecule is a fluorescent dye represented by formula (C);

(5) the anti-human MUC1 antibody Fab fragment of (1), wherein thedetectable molecule is a PET tracer or a MRI contrast medium;

(6) an anti-human MUC1 antibody Fab fragment wherein the detectablemolecule is a MRI contrast medium comprising a ligand represented byformula (A) and a paramagnetic metal ion, or a PET tracer comprising theligand and a metal radioisotope; and

(7) the anti-human MUC1 antibody Fab fragment of (6), wherein thedetectable molecule and the linker are a MRI contrast medium comprisinga ligand and a linker represented by formula (A′) and a paramagneticmetal ion, or a PET tracer comprising the ligand and the linker and ametal radioisotope.

The method mentioned above can be employed for the linking of theanti-human MUC1 antibody Fab fragment of the present invention to thedetectable molecule.

The conjugate of the present invention also includes a conjugate whichis a mixture of a plurality of conjugates of the present invention. Forexample, a conjugate which is mixture of a conjugate comprising alabeling moiety and a non-posttranslationally-modified anti-human MUC1antibody Fab fragment of the present invention, and a conjugatecomprising a labeling moiety and the anti-human MUC1 antibody Fabfragment of the present invention resulting from the posttranslationalmodification of the anti-human MUC1 antibody Fab fragment is alsoincluded in the conjugate of the present invention.

Certain embodiments of the conjugate of the present invention which is amixture of a plurality of conjugates of the present invention will beshown below:

(1) a conjugate which is a mixture of a conjugate wherein the labelingmoiety is a ligand and a linker represented by formula (A′), and theanti-human MUC1 antibody Fab fragment is an anti-human MUC1 antibody Fabfragment comprising a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4 and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6, and a conjugate whereinthe labeling moiety is a ligand and a linker represented by formula(A′), and the anti-human MUC1 antibody Fab fragment is an anti-humanMUC1 antibody Fab fragment comprising a heavy chain fragment derivedfrom a heavy chain fragment consisting of the amino acid sequencerepresented by SEQ ID NO: 4 by the modification of glutamine at aminoacid position 1 of SEQ ID NO: 4 into pyroglutamic acid, and a lightchain consisting of the amino acid sequence represented by SEQ ID NO: 6;(2) the conjugate of (1), further comprising a metal;(3) the conjugate of (2), wherein the metal is a metal radioisotope;(4) the conjugate of (3), wherein the metal is ⁸⁹Zr;(5) a conjugate which is a mixture of a conjugate wherein the labelingmoiety is a fluorescent dye represented by formula (B), and theanti-human MUC1 antibody Fab fragment is an anti-human MUC1 antibody Fabfragment comprising a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4 and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6, and a conjugate whereinthe labeling moiety is a fluorescent dye represented by formula (B), andthe anti-human MUC1 antibody Fab fragment is an anti-human MUC1 antibodyFab fragment comprising a heavy chain fragment derived from a heavychain fragment consisting of the amino acid sequence represented by SEQID NO: 4 by the modification of glutamine at amino acid position 1 ofSEQ ID NO: 4 into pyroglutamic acid, and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6; and(6) a conjugate which is a mixture of a conjugate wherein the labelingmoiety is a fluorescent dye represented by formula (C), and theanti-human MUC1 antibody Fab fragment is an anti-human MUC1 antibody Fabfragment comprising a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4 and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6, and a conjugate whereinthe labeling moiety is a fluorescent dye represented by formula (C), andthe anti-human MUC1 antibody Fab fragment is an anti-human MUC1 antibodyFab fragment comprising a heavy chain fragment derived from a heavychain fragment consisting of the amino acid sequence represented by SEQID NO: 4 by the modification of glutamine at amino acid position 1 ofSEQ ID NO: 4 into pyroglutamic acid, and a light chain consisting of theamino acid sequence represented by SEQ ID NO: 6.

<Polynucleotide of Present Invention>

The polynucleotide of the present invention includes a polynucleotidecomprising a nucleotide sequence encoding the heavy chain fragment ofthe anti-human MUC1 antibody Fab fragment of the present invention, anda polynucleotide comprising a nucleotide sequence encoding the lightchain of the anti-human MUC1 antibody Fab fragment of the presentinvention.

In one embodiment, the polynucleotide of the present invention is apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment comprising a heavy chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 8, or a polynucleotidecomprising a nucleotide sequence encoding a heavy chain fragmentcomprising a heavy chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 10.

Examples of the polynucleotide comprising a nucleotide sequence encodinga heavy chain fragment comprising a heavy chain variable regionconsisting of the amino acid sequence represented by SEQ ID NO: 8include a polynucleotide comprising the nucleotide sequence representedby SEQ ID NO: 7. Examples of the polynucleotide comprising a nucleotidesequence encoding a heavy chain fragment comprising a heavy chainvariable region consisting of the amino acid sequence represented by SEQID NO: 10 include a polynucleotide comprising the nucleotide sequencerepresented by SEQ ID NO: 9.

In one embodiment, the polynucleotide of the present invention is apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:2 or a polynucleotide comprising a nucleotide sequence encoding a heavychain fragment consisting of the amino acid sequence represented by SEQID NO: 4.

Examples of the polynucleotide comprising a nucleotide sequence encodinga heavy chain fragment consisting of the amino acid sequence representedby SEQ ID NO: 2 include a polynucleotide comprising the nucleotidesequence represented by SEQ ID NO: 1. Examples of the polynucleotidecomprising a nucleotide sequence encoding a heavy chain fragmentconsisting of the amino acid sequence represented by SEQ ID NO: 4include a polynucleotide comprising the nucleotide sequence representedby SEQ ID NO: 3.

In one embodiment, the polynucleotide of the present invention is apolynucleotide comprising a nucleotide sequence encoding a light chaincomprising a light chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 12.

Examples of the polynucleotide comprising a nucleotide sequence encodinga light chain comprising a light chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 12 include apolynucleotide comprising the nucleotide sequence represented by SEQ IDNO: 11.

In one embodiment, the polynucleotide of the present invention is apolynucleotide comprising a nucleotide sequence encoding a light chainconsisting of the amino acid sequence represented by SEQ ID NO: 6.

Examples of the polynucleotide comprising a nucleotide sequence encodinga light chain consisting of the amino acid sequence represented by SEQID NO: 6 include a polynucleotide comprising the nucleotide sequencerepresented by SEQ ID NO: 5.

The polynucleotide of the present invention is synthesizable through theuse of a gene synthesis method known in the art on the basis ofnucleotide sequences designed from the amino acid sequences of the heavychain fragment and the light chain of the anti-human MUC1 antibody Fabfragment of the present invention. Various methods known to thoseskilled in the art, such as methods for synthesizing an antibody genedescribed in International Publication No. WO 90/07861 can be used assuch gene synthesis methods.

<Expression Vector of Present Invention>

The expression vector of the present invention includes an expressionvector comprising a polynucleotide comprising a nucleotide sequenceencoding the heavy chain fragment of the anti-human MUC1 antibody Fabfragment of the present invention, an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment of the present invention,and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding the heavy chain fragment of the anti-humanMUC1 antibody Fab fragment of the present invention and a polynucleotidecomprising a nucleotide sequence encoding the light chain of theanti-human MUC1 antibody Fab fragment of the present invention.

The expression vector of the present invention preferably includes anexpression vector comprising a polynucleotide comprising a nucleotidesequence encoding a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4, an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a light chainconsisting of the amino acid sequence represented by SEQ ID NO: 6, andan expression vector comprising a polynucleotide comprising a nucleotidesequence encoding a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4 and a polynucleotide comprising anucleotide sequence encoding a light chain consisting of the amino acidsequence represented by SEQ ID NO: 6.

The expression vector of the present invention is not particularlylimited as long as a polypeptide encoded by the polynucleotide of thepresent invention can be produced in various host cells of prokaryoticcells and/or eukaryotic cells. Examples of such an expression vectorinclude plasmid vectors and virus vectors (e.g., adenovirus andretrovirus). Preferably, pEE6.4 or pEE12.4 (Lonza Ltd.) can be used.

The expression vector of the present invention can comprise a promoteroperably linked to a gene encoding the heavy chain fragment and/or thelight chain in the polynucleotide of the present invention. Examples ofthe promoter for expressing the Fab fragment of the present invention ina host cell include Trp promoter, lac promoter, recA promoter, XPLpromoter, lpp promoter, and tac promoter when the host cell is abacterium of the genus Escherichia. Examples of the promoter forexpression in yeasts include PH05 promoter, PGK promoter, GAP promoter,and ADH promoter. Examples of the promoter for expression in bacteria ofthe genus Bacillus include SL01 promoter, SP02 promoter, and penPpromoter. Examples thereof include promoters derived from viruses suchas CMV, RSV, and SV40, retrovirus promoter, actin promoter, EF(elongation factor) 1α promoter, and heat shock promoter when the hostis a eukaryotic cell such as a mammalian cell.

In the case of using a bacterium, particularly, E. coli, as a host cell,the expression vector of the present invention can further comprise astart codon, a stop codon, a terminator region and a replicable unit. Onthe other hand, in the case of using a yeast, an animal cell or aninsect cell as a host, the expression vector of the present inventioncan comprise a start codon and a stop codon. In this case, an enhancersequence, 5′ and 3′ untranslated regions of a gene encoding the heavychain fragment and/or the light chain of the present invention, asecretion signal sequence, a splicing junction, a polyadenylation site,or a replicable unit, etc. may be contained therein. Also, a selectivemarker usually used (e.g., tetracycline resistance gene, ampicillinresistance gene, kanamycin resistance gene, neomycin resistance gene,dihydrofolate reductase gene) may be contained therein according to apurpose.

<Transformed Host Cell of Present Invention>

The transformed host cell of the present invention includes a host celltransformed with the expression vector of the present invention,selected from the group consisting of the following (a) to (d):

(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention;

(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment of the present invention;

(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention and a polynucleotide comprising a nucleotide sequence encodingthe light chain of the anti-human MUC1 antibody Fab fragment of thepresent invention; and(d) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention and an expression vector comprising a polynucleotidecomprising a nucleotide sequence encoding the light chain of theanti-human MUC1 antibody Fab fragment of the present invention.

In one embodiment, the transformed host cell of the present invention isa host cell transformed with the expression vector of the presentinvention, selected from the group consisting of the following (a) to(d):

(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4;

(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a light chainconsisting of the amino acid sequence represented by SEQ ID NO: 6;

(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4 and a polynucleotide comprising a nucleotide sequence encoding a lightchain consisting of the amino acid sequence represented by SEQ ID NO: 6;and(d) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4 and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding a light chain consisting of the amino acidsequence represented by SEQ ID NO: 6.

The host cell to be transformed is not particularly limited as long asit is compatible with the expression vector used and can be transformedwith the expression vector to express the Fab fragment. Examples thereofinclude various cells such as natural cells and artificially establishedcells usually used in the technical field of the present invention(e.g., bacteria (bacteria of the genus Escherichia and bacteria of thegenus Bacillus), yeasts (the genus Saccharomyces, the genus Pichia,etc.), animal cells and insect cells (e.g., Sf9)), and mammalian celllines (e.g., cultured cells such as CHO-K1SV cells, CHO-DG44 cells, and293 cells). The transformation itself can be performed by a knownmethod, for example, a calcium phosphate method or an electroporationmethod.

<Method for Producing Anti-Human MUC1 Antibody Fab Fragment According toPresent Invention>

The method for producing an anti-human MUC1 antibody Fab fragmentaccording to the present invention comprises the step of culturing thetransformed host cell of the present invention to express the anti-humanMUC1 antibody Fab fragment.

In one embodiment, the transformed host cell of the present invention tobe cultured in the method for producing an anti-human MUC1 antibody Fabfragment according to the present invention is selected from the groupconsisting of the following (a) to (c):

(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention and a polynucleotide comprising a nucleotide sequence encodingthe light chain of the anti-human MUC1 antibody Fab fragment of thepresent invention;(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention and an expression vector comprising a polynucleotidecomprising a nucleotide sequence encoding the light chain of theanti-human MUC1 antibody Fab fragment of the present invention; and(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention, and a host cell transformed with an expression vectorcomprising a polynucleotide comprising a nucleotide sequence encodingthe light chain of the anti-human MUC1 antibody Fab fragment of thepresent invention.

A certain form of the transformed host cell of the present invention tobe cultured in the method for producing an anti-human MUC1 antibody Fabfragment according to the present invention is selected from the groupconsisting of the following (a) to (c):

(a) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4 and a polynucleotide comprising a nucleotide sequence encoding a lightchain consisting of the amino acid sequence represented by SEQ ID NO: 6;(b) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4 and an expression vector comprising a polynucleotide comprising anucleotide sequence encoding a light chain consisting of the amino acidsequence represented by SEQ ID NO: 6; and(c) a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a heavy chainfragment consisting of the amino acid sequence represented by SEQ ID NO:4, and a host cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding a light chainconsisting of the amino acid sequence represented by SEQ ID NO: 6.

Preferably, the transformed host cell of the present invention used is ahost cell transformed with an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the heavy chainfragment of the anti-human MUC1 antibody Fab fragment of the presentinvention and a polynucleotide comprising a nucleotide sequence encodingthe light chain of the anti-human MUC1 antibody Fab fragment of thepresent invention, or a host cell transformed with an expression vectorcomprising a polynucleotide comprising a nucleotide sequence encodingthe heavy chain fragment of the anti-human MUC1 antibody Fab fragment ofthe present invention and an expression vector comprising apolynucleotide comprising a nucleotide sequence encoding the light chainof the anti-human MUC1 antibody Fab fragment of the present invention.

In the method for producing an anti-human MUC1 antibody Fab fragmentaccording to the present invention, the transformed host cell can becultured in a nutrient medium. The nutrient medium preferably contains acarbon source, an inorganic nitrogen source or an organic nitrogensource necessary for the growth of the transformed host cell. Examplesof the carbon source include glucose, dextran, soluble starch, andsucrose. Examples of the inorganic nitrogen source or the organicnitrogen source include ammonium salts, nitrates, amino acids, cornsteep liquor, peptone, casein, meat extracts, soymeal, and potatoextracts. Also, other nutrients (e.g., inorganic salts (e.g., calciumchloride, sodium dihydrogen phosphate, and magnesium chloride),vitamins, and antibiotics (e.g., tetracycline, neomycin, ampicillin, andkanamycin)) may be contained therein, if desired.

The culture itself of the transformed host cell is performed by a knownmethod. Culture conditions, for example, temperature, medium pH andculture time, are appropriately selected. When the host is, for example,an animal cell, MEM medium (Science; 1952; 122: 501), DMEM medium(Virology; 1959; 8: 396-97), RPMI1640 medium (J. Am. Med. Assoc.; 1967;199: 519-24), 199 medium (Proc. Soc. Exp. Biol. Med.; 1950; 73:1-8), orthe like containing approximately 5 to 20% of fetal bovine serum can beused as a medium. The medium pH is preferably approximately 6 to 8. Theculture is usually performed at approximately 30 to 40° C. forapproximately 15 to 336 hours, and aeration or stirring can also beperformed, if necessary. When the host is an insect cell, examplesthereof include Grace's medium (PNAS; 1985; 82: 8404-8) containing fetalbovine serum. Its pH is preferably approximately 5 to 8. The culture isusually performed at approximately 20 to 40° C. for 15 to 100 hours, andaeration or stirring can also be performed, if necessary. When the hostis a bacterium, an actinomycete, a yeast, or a filamentous fungus, forexample, a liquid medium containing the nutrient source described aboveis appropriate. A medium of pH 5 to 8 is preferred. When the host is E.coli, preferred examples of the medium include LB medium and M9 medium(Miller et al., Exp. Mol. Genet, Cold Spring Harbor Laboratory; 1972:431). In such a case, the culture can usually be performed at 14 to 43°C. for approximately 3 to 24 hours with aeration or stirring, ifnecessary. When the host is a bacterium of the genus Bacillus, it canusually be performed at 30 to 40° C. for approximately 16 to 96 hourswith aeration or stirring, if necessary. When the host is a yeast,examples of the medium include Burkholder minimum medium (PNAS; 1980;77: 4505-8). Its pH is desirably 5 to 8. The culture is usuallyperformed at approximately 20 to 35° C. for approximately 14 to 144hours, and aeration or stirring can also be performed, if necessary.

The method for producing an anti-human MUC1 antibody Fab fragmentaccording to the present invention can comprise the step of recovering,preferably isolating or purifying, the expressed anti-human MUC1antibody Fab fragment, in addition to the step of culturing thetransformed host cell of the present invention to express the anti-humanMUC1 antibody Fab fragment. Examples of the isolation or purificationmethod include: methods exploiting solubility, such as salting out and asolvent precipitation method; methods exploiting difference in molecularweight, such as dialysis, ultrafiltration, gel filtration, and sodiumdodecyl sulfate-polyacrylamide gel electrophoresis; methods exploitingcharge, such as ion-exchange chromatography and hydroxylapatitechromatography; methods exploiting specific affinity, such as affinitychromatography; methods exploiting difference in hydrophobicity, such asreverse-phase high-performance liquid chromatography; and methodsexploiting difference in isoelectric point, such as isoelectricfocusing.

<Method for Producing Conjugate According to Present Invention>

The method for producing a conjugate according to the present inventioncomprises the step of covalently binding the anti-human MUC1 antibodyFab fragment of the present invention to a labeling moiety. The methodfor producing a conjugate according to the present invention may alsocomprise the steps of: culturing the transformed host cell of thepresent invention to express the anti-human MUC1 antibody Fab fragment;and covalently binding the Fab fragment to a labeling moiety. The methodfor producing a conjugate according to the present invention may alsocomprise the steps of: culturing the transformed host cell of thepresent invention to express the anti-human MUC1 antibody Fab fragment;recovering the expressed Fab fragment; and covalently binding the Fabfragment to a labeling moiety. The method for producing a conjugateaccording to the present invention may further comprise the step ofadding a metal. The linker, chelating agent, metal, or fluorescent dye,etc., and linking method used can employ those described in <Conjugateof present invention>.

In one embodiment, the method for producing a conjugate according to thepresent invention is a method comprising the steps of: culturing thetransformed host cell of the present invention to express the anti-humanMUC1 antibody Fab fragment; and covalently binding the Fab fragment to alabeling moiety. A certain embodiment of the method for producing aconjugate according to the present invention is a method comprising thesteps of: culturing the transformed host cell of the present inventionto express the anti-human MUC1 antibody Fab fragment; recovering theexpressed Fab fragment; and covalently binding the Fab fragment to alabeling moiety.

A certain embodiment of the method for producing a conjugate accordingto the present invention is a method comprising the steps of: culturingthe transformed host cell of the present invention to express theanti-human MUC1 antibody Fab fragment; and i) binding the Fab fragmentvia a linker to a ligand or ii) covalently binding the Fab fragmentdirectly to a ligand. A certain embodiment of the method for producing aconjugate according to the present invention is a method comprising thesteps of: culturing the transformed host cell of the present inventionto express the anti-human MUC1 antibody Fab fragment; recovering theexpressed Fab fragment; and i) binding the Fab fragment via a linker toa ligand or ii) covalently binding the Fab fragment directly to aligand.

A certain embodiment of the method for producing a conjugate accordingto the present invention is a method comprising the steps of: culturingthe transformed host cell of the present invention to express theanti-human MUC1 antibody Fab fragment; i) binding the Fab fragment via alinker to a ligand or ii) covalently binding the Fab fragment directlyto a ligand; and labeling the ligand of the conjugate with a metal(i.e., forming a chelate complex). A certain embodiment of the methodfor producing a conjugate according to the present invention is a methodcomprising the steps of: culturing the transformed host cell of thepresent invention to express the anti-human MUC1 antibody Fab fragment;recovering the expressed Fab fragment; i) binding the Fab fragment via alinker to a ligand or ii) covalently binding the Fab fragment directlyto a ligand; and labeling the ligand of the conjugate with a metal.

A certain embodiment of the method for producing a conjugate accordingto the present invention is a method comprising the steps of: culturingthe transformed host cell of the present invention to express theanti-human MUC1 antibody Fab fragment; i) binding the Fab fragment via alinker to a ligand or ii) covalently binding the Fab fragment directlyto a ligand; and labeling the ligand of the conjugate with a metalradioisotope (i.e., forming a chelate complex). A certain embodiment ofthe method for producing a conjugate according to the present inventionis a method comprising the steps of: culturing the transformed host cellof the present invention to express the anti-human MUC1 antibody Fabfragment; recovering the expressed Fab fragment; i) binding the Fabfragment via a linker to a ligand or ii) covalently binding the Fabfragment directly to a ligand; and labeling the ligand of the conjugatewith a metal radioisotope.

A certain embodiment of the method for producing a conjugate accordingto the present invention is a method comprising the steps of: culturingthe transformed host cell of the present invention to express theanti-human MUC1 antibody Fab fragment; and i) binding the Fab fragmentvia a linker to a fluorescent dye or ii) covalently binding the Fabfragment directly to a fluorescent dye. A certain embodiment of themethod for producing a conjugate according to the present invention is amethod comprising the steps of: culturing the transformed host cell ofthe present invention to express the anti-human MUC1 antibody Fabfragment; recovering the expressed Fab fragment; and i) binding the Fabfragment via a linker to a fluorescent dye or ii) covalently binding theFab fragment directly to a fluorescent dye.

A certain embodiment of the method for producing a conjugate accordingto the present invention is a method comprising the steps of: culturingthe transformed host cell of the present invention to express theanti-human MUC1 antibody Fab fragment; and labeling the Fab fragmentwith a detectable molecule. A certain embodiment of the method forproducing a conjugate according to the present invention is a methodcomprising the steps of: culturing the transformed host cell of thepresent invention to express the anti-human MUC1 antibody Fab fragment;recovering the expressed Fab fragment; and labeling the Fab fragmentwith a detectable molecule.

The method for producing a conjugate according to the present inventionmay be carried out as a method comprising two or more of the stepsdefined above as a series of steps or may be carried out as a methodcomprising at least one of the steps defined above. For example, amethod comprising the step of binding the anti-human MUC1 antibody Fabfragment of the present invention to a labeling moiety, and a methodcomprising the step of labeling the anti-human MUC1 antibody Fabfragment of the present invention bound to the labeling moiety with ametal are also included in the method for producing a conjugateaccording to the present invention. Also, the method for producing aconjugate according to the present invention includes a method having adifferent order of steps. For example, a method comprising labeling achelating agent with a metal, and then covalently binding the chelatingagent to the anti-human MUC1 antibody Fab fragment of the presentinvention is also included in the method for producing a conjugateaccording to the present invention.

<Composition for Diagnosis and Diagnosis Method>

The present invention relates to a composition for diagnosis comprisingthe conjugate of the present invention comprising a metal or afluorescent dye (hereinafter, referred to as the detectable conjugate ofthe present invention). The composition for diagnosis of the presentinvention may comprise one or more conjugate of the present invention.Specifically, the composition for diagnosis of the present invention maycomprise one conjugate of the present invention, or may comprise two ormore conjugates of the present invention in combination. The detectableconjugate of the present invention can be formulated according to aroutine method and utilized as an early diagnostic drug, a staging drugor a intraoperative diagnostic drug (particularly, a cancer diagnosticdrug). The intraoperative diagnostic drug means a diagnostic drugcapable of identifying a lesion site during operation such as surgery orendoscopic operation and examining its nature. In the case of using thecomposition for diagnosis of the present invention as an intraoperativediagnostic drug, the composition for diagnosis is administered to apatient, for example, 2 to 32 hours, 6 to 24 hours in a certainembodiment, or 2 hours in another embodiment, before operation.

The early diagnostic drug means a diagnostic drug aimed at performingdiagnosis when no condition is observed or at an early stage. Forexample, for cancers, it means a diagnostic drug that is used when nocondition is observed or at stage 0 or stage 1.

The staging drug means a diagnostic drug capable of examining the degreeof progression of a condition. For example, for cancers, it means adiagnostic drug capable of examining the stage thereof.

The cancer expected to be able to be diagnosed by the composition fordiagnosis of the present invention is a cancer expressing human MUC1.Examples of a certain embodiment include breast cancer, lung cancer,colorectal cancer, bladder cancer, skin cancer, thyroid gland cancer,stomach cancer, pancreatic cancer, kidney cancer, ovary cancer anduterine cervical cancer. Preferably, the cancer is breast cancer orbladder cancer.

The amount of the conjugate of the present invention added for theformulation of the composition for diagnosis of the present inventiondiffers depending on the degree of symptoms or age of a patient, thedosage form of a preparation used, or the binding titer of the Fabfragment, etc. For example, approximately 0.001 mg/kg to 100 mg/kg basedon the mass of the Fab fragment can be used per unit body weight of apatient.

Examples of the dosage form of the composition for diagnosis of thepresent invention can include parenteral agents such as injections andagents for drip infusion. Administration can be performed by intravenousinjection, local intramuscular injection to a target tissue,subcutaneous injection, intravesical administration, or the like. Forthe formulation, a carrier or an additive suitable for these dosageforms can be used in a pharmaceutically acceptable range. The type ofthe pharmaceutically acceptable carrier or additive is not particularlylimited, and a carrier or an additive well known to those skilled in theart can be used.

The present invention also relates to use of the detectable conjugate ofthe present invention for the production of a composition for the earlydiagnosis, a composition for the staging or a composition for theintraoperative diagnosis of a cancer. The present invention also relatesto the detectable conjugate of the present invention for use in theearly diagnosis, staging or intraoperative diagnosis of a cancer.

Further, the present invention also relates to a method for diagnosing acancer, comprising preoperatively or intraoperatively administering thedetectable conjugate of the present invention to a subject. In thiscontext, the “subject” is a human or any of other mammals in need ofreceiving the diagnosis. A certain embodiment is a human in need ofreceiving the diagnosis. The effective amount of the detectableconjugate of the present invention in the diagnosis method of thepresent invention may be the same amount as the effective amount of theconjugate of the present invention for the formulation described above.In the diagnosis method of the present invention, the detectableconjugate of the present invention is preferably administered by localintramuscular injection to a target tissue, subcutaneous injection, orthe like. In the diagnosis method of the present invention, in the caseof preoperatively administering the conjugate of the present invention,the conjugate is administered to a patient, for example, 2 to 48 hours,6 to 24 hours in a certain embodiment, and 2 hours in another embodimentbefore operation.

In an alternative embodiment, the present invention also relates to useof the anti-human MUC1 antibody Fab fragment of the present inventionfor the production of the conjugate of the present invention. In acertain embodiment, the present invention also relates to use of theanti-human MUC1 antibody Fab fragment of the present invention for theproduction of a composition for diagnosis comprising the conjugate ofthe present invention.

As for a embodiment in which the composition for diagnosis of thepresent invention comprising a metal radioisotope is provided, it may belabeled with the metal radioisotope immediately before use or may beprovided as a composition for diagnosis comprising the metalradioisotope.

<Composition for Treatment and Treatment Method>

The present invention includes a pharmaceutical composition comprisingone or more conjugate of the present invention and a pharmaceuticallyacceptable excipient. Specifically, the composition for treatment of thepresent invention may comprise one conjugate of the present invention,or may comprise two or more conjugates of the present invention incombination. The conjugate of the present invention can be used in thepreparation of a pharmaceutical composition by a method usually usedusing an excipient usually used in the art, i.e., a pharmaceuticalexcipient, a pharmaceutical carrier, or the like. Examples of the dosageforms of these pharmaceutical compositions include parenteral agentssuch as injections and agents for drip infusion. Administration can beperformed by intravenous injection, subcutaneous injection, intravesicaladministration, or the like. For the formulation, an excipient, acarrier, an additive, or the like suitable for these dosage forms can beused in a pharmaceutically acceptable range.

The amount of the conjugate of the present invention added for theformulation described above differs depending on the degree of symptomsor age of a patient, the dosage form of a preparation used, or thebinding titer of the Fab fragment, etc. For example, approximately 0.001mg/kg to 100 mg/kg based on the mass of the Fab fragment can be used perunit body weight of a patient.

The pharmaceutical composition comprising the conjugate of the presentinvention can be used for the treatment of a cancer. The cancer expectedto be able to be treated by the pharmaceutical composition comprisingthe conjugate of the present invention is a cancer expressing humanMUC1. Examples thereof include breast cancer, lung cancer, colorectalcancer, bladder cancer, skin cancer, thyroid gland cancer, stomachcancer, pancreatic cancer, kidney cancer, ovary cancer and uterinecervical cancer.

A certain embodiment of the pharmaceutical composition comprising theconjugate of the present invention is a pharmaceutical compositioncomprising the conjugate comprising a fluorescent dye and can be used inthe treatment of a cancer by application to a photoimmunotherapy method.The photoimmunotherapy method is a method of allowing the conjugatecomprising a fluorescent dye to specifically accumulate in cancertissues, followed by irradiation with light having a wavelength excitingthe fluorescent dye contained in the conjugate to induce cell death in acancer-specific manner through the phototoxic effect of the fluorescentdye. In the case of using the conjugate of the present inventioncomprising a fluorescent dye in the photoimmunotherapy method, thewavelength of the light for irradiation can be a near-infraredwavelength (650 to 1000 nm).

The present invention includes a pharmaceutical composition for treatingbreast cancer or bladder cancer, comprising the conjugate of the presentinvention. The present invention also includes a method for treatingbreast cancer or bladder cancer, comprising the step of administering atherapeutically effective amount of the conjugate of the presentinvention, which can comprise the step of performing irradiation withlight having a near-infrared wavelength (650 to 1000 nm, for example,660 to 740 nm, for example, 680 nm), in addition to the step describedabove. A certain embodiment of the dose of light irradiation is at least1 J/cm². A certain embodiment is at least 10 J/cm². A certain embodimentis at least 100 J/cm². A certain embodiment is 1 to 500 J/cm². A certainembodiment is 50 to 200 J/cm^(Z). In a certain embodiment, theirradiation may be carried out a plurality of times after administrationof the conjugate of the present invention. The present invention alsoincludes a method for inducing the cell death of cancer cells of breastcancer or bladder cancer, comprising the step of administering atherapeutically effective amount of the conjugate of the presentinvention.

The pharmaceutical composition for treating a cancer can also be used inthe diagnosis of a cancer. For example, the pharmaceutical compositionfor treating breast cancer or bladder cancer can also be used in thediagnosis of the cancer.

The present invention also includes the conjugate of the presentinvention for use in the treatment of breast cancer or bladder cancer.The present invention further includes use of the conjugate of thepresent invention for the production of a pharmaceutical composition fortreating breast cancer or bladder cancer.

In an alternative embodiment, the present invention also relates to useof the anti-human MUC1 antibody Fab fragment of the present inventionfor the production of a pharmaceutical composition comprising theconjugate of the present invention.

The present invention is generally described above. Particular Exampleswill be provided here for reference in order to obtain furtherunderstanding. However, these are given for illustrative purposes and donot limit the present invention.

EXAMPLES Example 1: Preparation of Anti-Human MUC1 Antibody Fab Fragment

Two anti-human MUC1 antibody Fab fragments designated as P10-1 Fab andP10-2 Fab were prepared.

The amino acid sequences of the heavy chain variable regions and thelight chain variable regions of P10-1 Fab and P10-2 Fab werespecifically designed as sequences expected to improve affinity and notto attenuate affinity even by the binding of a labeling moiety, by usinga molecular model of a humanized antibody constructed in accordance withthe literature (Proteins, 2014 August; 82 (8): 1624-35) afterhumanization of a 1B2 antibody, which is a mouse-derived anti-humancancer-specific MUC1 antibody, with reference to the method described inthe literature (Front Biosci., 2008 Jan. 1; 13: 1619-33).

GS vector pEE6.4 (Lonza Ltd.) having an insert of a heavy chain fragmentgene formed by connecting a gene encoding a signal sequence(MEWSWVFLFFLSVTTGVHS (SEQ ID NO: 13)) to the 5′ side of the heavy chainvariable region gene of P10-1 Fab or P10-2 Fab and connecting a humanIgγ1 constant region gene (consisting of a nucleotide sequence fromnucleotide positions 355 to 669 of SEQ ID NO: 1 or 3) to the 3′ sidethereof was prepared. Here, in order to express each Fab fragment, astrop codon was inserted to downstream of a codon of Asp at position 221based on the EU index provided by Kabat et al. (corresponding to Asp atposition 222 in the amino acid sequences of SEQ ID NOs: 2 and 4mentioned later) in the heavy chain constant region gene. Also, GSvector pEE12.4 (Lonza Ltd.) having an insert of a light chain geneformed by connecting a gene encoding a signal sequence(MSVPTQVLGLLLLWLTDARC (SEQ ID NO: 14)) to the 5′ side of the commonlight chain variable region gene of P10-1 Fab and P10-2 Fab andconnecting a human κ chain constant region gene (consisting of anucleotide sequence from nucleotide positions 340 to 660 of SEQ ID NO:5) to the 3′ side thereof was prepared.

The expression of each Fab fragment was performed by the method oftransient expression. Expi293F cells (Thermo Fisher Scientific Inc.)cultured into approximately 2500000 cells/mL in Expi293 ExpressionMedium (Thermo Fisher Scientific Inc.) were transfected with the GSvectors of the heavy chain fragment and the light chain mentioned aboveusing ExpiFectamine 293 Transfection Kit (Thermo Fisher ScientificInc.), and cultured for 8 days. After expression, the culturesupernatant was purified using KappaSelect (GE Healthcare Japan Corp.)to obtain each Fab fragment.

The nucleotide sequence of the heavy chain fragment of P10-1 Fab isshown in SEQ ID NO: 1, and the amino acid sequence encoded thereby isshown in SEQ ID NO: 2. The nucleotide sequence of the heavy chainvariable region of P10-1 Fab is shown in SEQ ID NO: 7. The amino acidsequence encoded thereby is shown in SEQ ID NO: 8.

The nucleotide sequence of the heavy chain fragment of P10-2 Fab isshown in SEQ ID NO: 3. The amino acid sequence encoded thereby is shownin SEQ ID NO: 4. The nucleotide sequence of the heavy chain variableregion of P10-2 Fab is shown in SEQ ID NO: 9. The amino acid sequenceencoded thereby is shown in SEQ ID NO: 10.

The light chain is common in P10-1 Fab and P10-2 Fab. The nucleotidesequence thereof is shown in SEQ ID NO: 5. The amino acid sequenceencoded thereby is shown in SEQ ID NO: 6. The nucleotide sequence of thelight chain variable region of P10-1 Fab and P10-2 Fab is shown in SEQID NO: 11. The amino acid sequence encoded thereby is shown in SEQ IDNO: 12.

Example 2: Amino Acid Modification Analysis of Fab Fragment

As a result of analyzing the amino acid modification of purified P10-2Fab, it was suggested that heavy chain N-terminal glutamine was modifiedinto pyroglutamic acid in a great majority of purified antibodies.

Example 3: Binding Activity Evaluation of Fab Fragment

Binding activity against human cancer-specific MUC1 was compared as toP10-1 Fab and P10-2 Fab expressed by the method mentioned above with achimeric 1B2 antibody Fab fragment (hereinafter, referred to as 1B2 Fab;prepared by linking a human IgG1 CH1 domain and a κ chain CL domain tothe VH domain and the VL domain (their sequence information was quotedfrom Patent Literature 1), respectively, of the 1B2 antibody (PatentLiterature 1); for the convenience of linking of the CH1 domain and theCL domain, an alanine residue at position 113 based on the EU index(Kabat et al.) in the VH domain was substituted by a serine residue, andan alanine residue at position 109 based on the EU index (Kabat et al.)in the VL domain was substituted by a threonine residue) by Cell ELISA.Specifically, breast cancer cell line T-47D cells (purchasable fromATCC; HTB-133) expressing human cancer-specific MUC1 were inoculated at0.75×10⁴ cells per well to a 96-well ELISA plate coated with collagen I,and cultured overnight. Then, the cells were fixed in formalin, andP10-1 Fab, P10-2 Fab or 1B2 Fab described above was reacted therewith.Then, a horseradish peroxidase (HRP)-labeled goat anti-human Igκantibody (Southern Biotechnology Associates, Inc.) was reacted as asecondary antibody. ECL Prime Western Blotting Detection Reagent (GEHealthcare Japan Corp.) was added thereto for luminescence, and thedegree of the luminescence was examined. As a result, as shown in FIG. 1, P10-1 Fab and P10-2 Fab were confirmed to have approximately 10 ormore times the binding activity against human cancer-specific MUC1compared to 1B2 Fab.

Example 4: Fluorescent Labeling of Fab Fragment

Subsequently, the present inventors labeled P10-1 Fab, P10-2 Fab and 1B2Fab with a fluorescent dye mentioned above.

Specifically, each Fab fragment solution adjusted to approximately 1mg/mL with phosphate-buffered saline (pH 7.4) was adjusted to pH 8.5 bythe addition of a 1/10 amount of a 1 M dipotassium hydrogen phosphatesolution (pH 9). IRDye800CW NHS Ester (LI-COR Bioscience, Inc.) wasadded thereto at a final concentration of 310.8 μg/mL, and the resultantwas stirred at room temperature under shading for 2 hours. IRDye800CWNHS Ester has a N-hydroxysuccinimide group and therefore reactsimmediately with Lys of the Fab fragment. This was recovered throughAmicon Ultra 3K-0.5 mL centrifugal filter (Merck Millipore) to purify afluorescently labeled Fab fragment. P10-1 Fab, P10-2 Fab and 1B2 Fabharboring this fluorescent dye were designated as P10-1 Fab Dye, P10-2Fab Dye and 1B2 Fab Dye.

Example 5: Binding Activity Evaluation of Fluorescently Labeled FabFragment

Binding activity against human cancer-specific MUC1 was compared as toP10-1 Fab Dye and P10-2 Fab Dye labeled by the method mentioned abovewith 1B2 Fab Dye by Cell ELISA. Specifically, breast cancer cell lineT-47D cells expressing human cancer-specific MUC1 were inoculated at0.75×10⁴ cells per well to a 96-well ELISA plate coated with collagen I,and cultured overnight. Then, the cells were fixed in formalin, andP10-1 Fab Dye, P10-2 Fab Dye or 1B2 Fab Dye described above was reactedtherewith. Then, a HRP-labeled goat anti-human Igκ antibody (SouthernBiotechnology Associates, Inc.) was reacted as a secondary antibody. ECLPrime Western Blotting Detection Reagent (GE Healthcare Japan Corp.) wasadded thereto for luminescence, and the degree of the luminescence wasexamined. As a result, as shown in FIG. 2 , the binding activity of 1B2Fab Dye was attenuated by labeling, whereas P10-1 Fab Dye and P10-2 FabDye were confirmed to be free from the attenuation of the bindingactivity by labeling.

Example 6: Labeling of Fab Fragment with Chelating Agent

Subsequently, the present inventors labeled P10-2 Fab with a chelatingagent mentioned above.

Specifically, a Fab fragment solution adjusted to 12.5 mg/mL withphosphate-buffered saline (pH 7.4) was adjusted to pH 9.0 by theaddition of a 100 M sodium carbonate solution at 10 mM.p-SCN-Bn-deferoxamine (Macrocyclics, Inc.) was added thereto at a finalconcentration of 1 mM, and the resultant was reacted at 37° C. for 2hours. p-SCN-Bn-deferoxamine has an isothiocyanate group and thereforereacts immediately with Lys of the Fab fragment. This was recoveredthrough Amicon Ultra 10K-0.5 mL centrifugal filter to purify a chelatingagent-labeled Fab fragment. This chelating agent-labeled P10-2 Fab wasdesignated as P10-2 Fab DFO.

Example 7: Binding Activity Evaluation of Chelating Agent-Labeled FabFragment

Binding activity against human cancer-specific MUC1 was compared as toP10-2 Fab DFO labeled by the method mentioned above with P10-2 Fab byCell ELISA. Specifically, T-47D cells expressing human cancer-specificMUC1 were inoculated at 0.75×10⁴ cells to a 96-well ELISA plate coatedwith collagen I, and cultured overnight. Then, the cells were fixed informalin, and P10-2 Fab DFO or P10-2 Fab described above was reactedtherewith. Then, a HRP-labeled goat anti-human Igκ antibody (SouthernBiotechnology Associates, Inc.) was reacted as a secondary antibody. ECLPrime Western Blotting Detection Reagent (GE Healthcare Japan Corp.) wasadded thereto for luminescence, and the degree of the luminescence wasexamined. As a result, as shown in FIG. 3 , P10-2 Fab DFO and P10-2 Fabhad equivalent binding activity. P10-2 Fab was confirmed to be free fromthe attenuation of the binding activity by labeling with a chelatingagent.

Example 8: Reactivity of P10-2 in Human Bladder Cancer Tissue Sample

In order to study the reactivity of P10-2 Fab in human bladder cancer,the study was made by immunostaining using a human bladder cancer tissuearray (US Biomax, Inc., BC12011b). When P10-2 Fab is used as a primaryantibody, an anti-human antibody used as a secondary antibodycross-reacts with human tissues. Therefore, mouse chimeric P10-2 IgG(antibody in which the VH domain and the VL domain of P10-2 Fab werefused with mouse IgG2a CH1 to CH3 domains and a mouse κ chain CL domain,respectively) was prepared and used as a primary antibody. The humanbladder cancer tissue array sample was reacted with a 3% hydrogenperoxide solution for 5 minutes and then washed with phosphate-bufferedsaline of pH 7.4. Then, mouse chimeric P10-2 IgG (0.25 μg/mL) wasreacted, and then, One-Step Polymer-HRP antibody (BioGenex) was reactedas a secondary antibody. Super Sensitive DAB (BioGenex) was addedthereto for color development. The positive reaction of staining forcancer tissues was determined as ±: very mildly positive, +: positive,++: moderately positive, and +++: highly positive, and one case whosecancer tissues were not clear was excluded. As a result, positivereaction was found in 57 out of 59 studied cases with 11 cases for ±, 24cases for +, 17 cases for ++, and 5 cases for +++ (positive rate: 97%).

Example 9: Labeling of Chelated Fab Fragment with ⁸⁹Zr

⁸⁹Zr used was dissolved in a 1 M aqueous oxalic acid solution andproduced as ⁸⁹Zr-Oxalate (Okayama University). 20 μL of ⁸⁹Zr-Oxalate(21.4 MBq) was neutralized with 10 L of a 2 M aqueous sodium carbonatesolution. Then, 70 μL of a 5 mg/mL solution of gentisic acid dissolvedin 250 mM aqueous sodium acetate solution was added thereto. Further,200 μL of a 500 mM aqueous HEPES(4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) solution containing0.1% polysorbate 80 and 20% glycerol was added thereto. To this solutioncontaining ⁸⁹Zr, 100 μL of 9.5 mg/mL P10-2 Fab DFO was added and reactedat room temperature for 30 minutes. The obtained reaction mixture waspurified using Amicon Ultra 10K-0.5 mL centrifugal filter (MerckMillipore) and further filtered through a membrane filter (Millex-GV0.22 m 13 mm; Merck Millipore) to obtain ⁸⁹Zr-labeled P10-2 Fab DFO(16.1 MBq) of interest. This ⁸⁹Zr-labeled P10-2 Fab DFO was designatedas P10-2 Fab DFO ⁸⁹Zr. The obtained P10-2 Fab DFO ⁸⁹Zr solution wasanalyzed using high-performance liquid chromatography (20AD series;Shimadzu Corp.). The retention time (UV: 10.192 min) of P10-2 Fab DFOwas compared with the retention time (UV: 10.178 min, RI: 10.515 min) ofP10-2 Fab DFO ⁸⁹Zr. The respective retention times were equivalent,confirming that P10-2 Fab DFO was labeled with ⁸⁹Zr. The HPLC analysiswas carried out under the following conditions: column: BioSep SEC s3000300×7.8 mm (Phenomenex Inc.), column temperature: room temperature, UVdetector wavelength: 280 nm, mobile phase: phosphate buffer solution(Gibco, 10010-023), flow rate: 1 mL/min.

Example 10: Labeling of Fab Fragment with IRDye700DX

IRDye700DX NHS Ester (LI-COR Bioscience, Inc.) was used to label P10-2Fab with IRDye700DX.

Specifically, a P10-2 Fab solution adjusted to 1 mg/mL withphosphate-buffered saline (pH 7.4) was supplemented with a 1/10 amountof a 1 M dipotassium hydrogen phosphate solution (pH 9). IRDye700DX NHSEster was added thereto at a final concentration of 154 μg/mL, and theresultant was stirred at room temperature for 2 hours. After reaction,IRDye700DX-labeled P10-2 Fab was purified by recovery through AmiconUltra 10K-15 mL centrifugal filter (Merck Millipore). ThisIRDye700DX-labeled P10-2 Fab was designated as P10-2 Fab IR700.

Example 11: Binding Activity Evaluation of Fab Fragment Against BreastCancer Cell Line and Bladder Cancer Cell Line

The binding activity of P10-2 Fab in human breast cancer and bladdercancer was studied.

Specifically, human breast cancer cell line MDA-MB-468 cells(purchasable from ATCC; HTB-132; hereinafter, referred to as MM-468cells) or human bladder cancer cell line 647-V cells (purchasable fromDSMZ; ACC 414) expressing human cancer-specific MUC1 were inoculated at1×10⁴ cells per well to a 96-well ELISA plate and cultured overnight.Then, P10-2 Fab described above was reacted at a concentration of0.0000003 to 0.001 mg/mL. Then, a horseradish peroxidase (HRP)-labeledgoat anti-human IgG antibody (Medical & Biological Laboratories Co.,Ltd.) was reacted as a secondary antibody. ECL Prime Western BlottingDetection Reagent (GE Healthcare Japan Corp.) was added thereto forluminescence, and the degree of the luminescence was examined. As aresult, as shown in FIG. 4 , P10-2 Fab was found to have bindingactivity against the human breast cancer cell line MM-468 cells and thehuman bladder cancer cell line 647-V cells.

Example 12: Contrast Evaluation of Fluorescently Labeled Fab Fragment inSubcutaneously Cancer-Bearing Model

3×10⁶ human breast cancer cell line MM-468 cells were subcutaneouslytransplanted as human cancer-specific MUC1-positive cells to the rightback of each immunodeficient mouse (SCID mouse; Charles RiverLaboratories Japan, Inc.). Mice having tumorigenesis were selectedapproximately one month after the transplantation. P10-2 Fab Dyedissolved in phosphate-buffered saline (pH 7.4) was intravenouslyadministered at a dose of 0.1, 0.3, 1 or 3 mg/kg (N=2 for the 0.1 mg/kgadministration group, and N=3 for the 0.3, 1 and 3 mg/kg administrationgroups). Photographs were taken with a usual camera and a near-infraredfluorescence camera (Fluobeam (800 nm filter); Fluoptics) 6 hours and 24hours after the P10-2 Fab Dye administration. The fluorescent brightnessof a tumor site and a peritumoral background site in the image takenwith the infrared fluorescence camera was measured. As a result, asshown in FIG. 5A, P10-2 Fab Dye was found to accumulate in the humancancer-specific MUC1-positive MM-468 tumor site and be clearly visiblein the fluorescent image 6 hours after administration. As shown in FIG.5B, the tumor/background ratio was found to elevate in a P10-2 Fab Dyedose-dependent manner in the range of 0.1 to 3 mg/kg. It was furtherobvious that the effect was sustained even 24 hours afteradministration. These results demonstrated that P10-2 Fab Dye permitsdetection of human MUC1-positive cancer cells from 6 hours to 24 hoursafter administration.

Example 13: Detection of Tumor with IRDye700DX Labeled Fab Fragment

5×10⁶ MM-468 cells were subcutaneously transplanted to the right back ofeach immunodeficient mouse (nude mouse; Charles River LaboratoriesJapan, Inc.). This test was conducted at N=2. P10-2 Fab IR700 (3 mg/kg)or a vehicle (phosphate-buffered saline) was intravenously administered40 days after the transplantation. The animals were euthanized 2 hoursafter the P10-2 Fab IR700 administration. Tumor was excised, and theluminescence of the tumor sites was measured by excitation at awavelength of 675 nm and detection at a wavelength of 740 nm in IVISSPECTRUM (PerkinElmer, Inc.). As a result, as shown in FIG. 6 , P10-2Fab IR700 was found to accumulate in MM-468 cells 2 hours afteradministration.

Example 14: Cytotoxicity Evaluation of IRDye700DX Labeled Fab Fragment

In order to study the utilization of P10-2 Fab IR700 in cancertreatment, cytotoxicity in photoimmunotherapy was evaluated.

Specifically, human breast cancer cell line MM-468 cells, human bladdercancer cell line 647-V cells or CHO-K1 cells of Comparative Example(purchasable from ATCC; CCL-61) were inoculated at 5×10³ cells per wellto a 384-well white plate and cultured overnight. Then, P10-2 Fab IR700was reacted at 0, 0.01, 0.1, or 1 μg/mL and then irradiated with 0 to 30J/cm² of light having a wavelength of 680 nm. After the lightirradiation, overnight culture was performed. CellTiter-Glo (PromegaCorp.) was added thereto for luminescence, and the luminescence wasmeasured to measure the number of live cells. This test was conductedusing 3 wells under each condition. As a result, as shown in FIG. 7 , itwas obvious that P10-2 Fab IR700 exhibits cytotoxicity in a mannerspecific for the expression of human cancer-specific MUC1 by lightirradiation.

Example 15: Antitumor Activity Evaluation of IRDye700DX Labeled FabFragment

5×10⁶ MM-468 cells were subcutaneously transplanted to the right back ofeach immunodeficient mouse (nude mouse; Charles River LaboratoriesJapan, Inc.). This test was conducted at N=4. After tumor volume became300 mm³, P10-2 Fab IR700 (0.3, 1, or 3 mg/kg) was intravenouslyadministered at days 1, 5, 8, 12 and 15. Phosphate-buffered saline wassimilarly administered to a vehicle group. On the day following the drugadministration, irradiation with 0 or 200 J/cm² of light having awavelength of 680 nm was performed, and the tumor volume was measuredover time. As a result, as shown in FIG. 8 , it was obvious that P10-2Fab IR700 showed an antitumor effect in a manner dependent on a dose andlight irradiation.

INDUSTRIAL APPLICABILITY

The anti-human MUC1 antibody Fab fragment of the present invention isexpected to be useful in the diagnosis and/or treatment of cancers suchas breast cancer, lung cancer, colorectal cancer, bladder cancer, skincancer, thyroid gland cancer, stomach cancer, pancreatic cancer, kidneycancer, ovary cancer or uterine cervical cancer.

SEQUENCE LISTING FREE TEXT

SEQ ID NO: 1: Nucleotide sequence of DNA encoding a P10-1 Fab heavychain fragment

SEQ ID NO: 2: Amino acid sequence of the P10-1 Fab heavy chain fragment

SEQ ID NO: 3: Nucleotide sequence of DNA encoding a P10-2 Fab heavychain fragment

SEQ ID NO: 4: Amino acid sequence of the P10-2 Fab heavy chain fragment

SEQ ID NO: 5: Nucleotide sequence of DNA encoding an antibody lightchain

SEQ ID NO: 6: Amino acid sequence of the antibody light chain

SEQ ID NO: 7: Nucleotide sequence of DNA encoding a P10-1 Fab heavychain variable region

SEQ ID NO: 8: Amino acid sequence of the P10-1 Fab heavy chain variableregion

SEQ ID NO: 9: Nucleotide sequence of DNA encoding a P10-2 Fab heavychain variable region

SEQ ID NO: 10: Amino acid sequence of the P10-2 Fab heavy chain variableregion

SEQ ID NO: 11: Nucleotide sequence of DNA encoding an antibody lightchain variable region

SEQ ID NO: 12: Amino acid sequence of the antibody light chain variableregion

SEQ ID NO: 13: Heavy chain signal sequence

SEQ ID NO: 14: Light chain signal sequence

SEQ ID NO: 15: Tandem repeat sequence of the extracellular domain ofMUC1

The invention claimed is:
 1. A conjugate, comprising one or morelabeling moieties and an anti-human MUC1 antibody fab fragment, whereinsaid anti-human MUC1 antibody Fab fragment is selected from the groupconsisting of the following (a) and (b): (a) an anti-human MUC1 antibodyFab fragment comprising a heavy chain fragment comprising a heavy chainvariable region consisting of the amino acid sequence represented by SEQID NO: 8 or SEQ ID NO: 10 and a light chain comprising a light chainvariable region consisting of the amino acid sequence represented by SEQID NO: 12; and (b) an anti-human MUC1 antibody Fab fragment comprising aheavy chain fragment comprising a heavy chain variable region derivedfrom a heavy chain variable region consisting of the amino acid sequencerepresented by SEQ ID NO: 8 or SEQ ID NO: 10 by the modification ofglutamine at amino acid position 1 of SEQ ID NO: 8 or SEQ ID NO: 10 intopyroglutamic acid, and a light chain comprising a light chain variableregion consisting of the amino acid sequence represented by SEQ ID NO:12; and said anti-human MUC1 antibody Fab fragment is bound to 1 to 11labeling moieties.
 2. The conjugate according to claim 1, wherein saidanti-human MUC1 antibody Fab fragment is selected from the groupconsisting of the following (a) and (b): (a) an anti-human MUC1 antibodyFab fragment comprising a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 2 or SEQ ID NO: 4 and a lightchain consisting of the amino acid sequence represented by SEQ ID NO: 6;and (b) an anti-human MUC1 antibody Fab fragment comprising a heavychain fragment derived from a heavy chain fragment consisting of theamino acid sequence represented by SEQ ID NO: 2 or SEQ ID NO: 4 by themodification of glutamine at amino acid position 1 of SEQ ID NO: 2 orSEQ ID NO: 4 into pyroglutamic acid, and a light chain consisting of theamino acid sequence represented by SEQ ID NO:
 6. 3. The conjugateaccording to claim 1, wherein said anti-human MUC1 antibody Fab fragmentis selected from the group consisting of the following (a) and (b): (a)an anti-human MUC1 antibody Fab fragment comprising a heavy chainfragment comprising a heavy chain variable region consisting of theamino acid sequence represented by SEQ ID NO: 10 and a light chaincomprising a light chain variable region consisting of the amino acidsequence represented by SEQ ID NO: 12; and (b) an anti-human MUC1antibody Fab fragment comprising a heavy chain fragment comprising aheavy chain variable region derived from a heavy chain variable regionconsisting of the amino acid sequence represented by SEQ ID NO: 10 bythe modification of glutamine at amino acid position 1 of SEQ ID NO: 10into pyroglutamic acid, and a light chain comprising a light chainvariable region consisting of the amino acid sequence represented by SEQID NO:
 12. 4. The conjugate according to claim 3, wherein saidanti-human MUC1 antibody Fab fragment is selected from the groupconsisting of the following (a) and (b): (a) an anti-human MUC1 antibodyFab fragment comprising a heavy chain fragment consisting of the aminoacid sequence represented by SEQ ID NO: 4 and a light chain consistingof the amino acid sequence represented by SEQ ID NO: 6; and (b) ananti-human MUC1 antibody Fab fragment comprising a heavy chain fragmentderived from a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4 by the modification of glutamine atamino acid position 1 of SEQ ID NO: 4 into pyroglutamic acid, and alight chain consisting of the amino acid sequence represented by SEQ IDNO:
 6. 5. The conjugate according to claim 4, wherein said anti-humanMUC1 antibody Fab fragment is an anti-human MUC1 antibody Fab fragmentcomprising a heavy chain fragment consisting of the amino acid sequencerepresented by SEQ ID NO: 4 and a light chain consisting of the aminoacid sequence represented by SEQ ID NO:
 6. 6. The conjugate according toclaim 4, wherein said anti-human MUC1 antibody Fab fragment is ananti-human MUC1 antibody Fab fragment comprising a heavy chain fragmentderived from a heavy chain fragment consisting of the amino acidsequence represented by SEQ ID NO: 4 by the modification of glutamine atamino acid position 1 of SEQ ID NO: 4 into pyroglutamic acid, and alight chain consisting of the amino acid sequence represented by SEQ IDNO:
 6. 7. The conjugate according to any one of claims 1-6, wherein thelabeling moiety is (i) a ligand and a linker or (ii) a ligand.
 8. Theconjugate according to claim 7, wherein the ligand is a ligandrepresented by the following formula (A):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment or the linker.
 9. The conjugate according to claim 8,wherein the labeling moiety is a ligand and a linker represented by thefollowing formula (A′):

wherein the wavy line represents binding to the anti-human MUC1 antibodyFab fragment.
 10. The conjugate according to claim 9, wherein theanti-human MUC1 antibody Fab fragment is bound via an amino groupthereof to the carbon atom of a labeling moiety terminal C(=S) group.11. A conjugate selected from the group consisting of the following (a)to (c): (a) the conjugate according to claim 10 wherein the anti-humanMUC1 antibody Fab fragment is the anti-human MUC1 antibody Fab fragmentaccording to claim 5; (b) the conjugate according to claim 10 whereinthe anti-human MUC1 antibody Fab fragment is the anti-human MUC1antibody Fab fragment according to claim 6; and (c) a conjugate which isa mixture of (a) and (b).
 12. The conjugate according to claim 11,further comprising 89Zr.
 13. A pharmaceutical composition comprising oneor more conjugates according to claim 1, and a pharmaceuticallyacceptable carrier.
 14. A pharmaceutical composition comprising one ormore conjugates according to claim 12 and a pharmaceutically acceptablecarrier.
 15. A method for diagnosing breast cancer or bladder cancer,comprising preoperatively or intraoperatively administering theconjugate according to claim 1 to a subject.
 16. A method for treatingbreast cancer or bladder cancer, comprising administering atherapeutically effective amount of the conjugate according to claim 1to a subject in need thereof.
 17. The conjugate according to claim 10,wherein said anti-human MUC1 antibody Fab fragment is bound to 1 to 7labeling moieties.
 18. The conjugate according to claim 11, wherein saidanti-human MUC1 antibody Fab fragment is bound to 1 to 4 labelingmoieties.
 19. The conjugate according to any one of claims 8 to 11, 17,and 18, further comprising a metal.
 20. The conjugate according to claim19, wherein the metal is a metal radioisotope.
 21. The conjugateaccording to claim 20, wherein the metal is ⁸⁹Zr.